Location aware steering using fine timing measurement (FTM) frames in a wireless local area network (WLAN)

ABSTRACT

This disclosure provides methods, devices and systems for access point (AP) steering or frequency band steering based on a location of a station (STA). In some aspects, an AP may determine the location of the STA based on timing information and may steer the STA based on the location. To obtain the timing information, the AP may exchange fine timing measurement (FTM) frames with the STA. The AP may determine a distance between itself and the STA based on the timing information. The AP also may obtain distance information from other APs. Using the distance between itself and the STA, as well as the distance information from other APs, the AP may determine a location of the STA and steer the STA based on its location. The AP may steer the STA to a different frequency band of the same AP or to different AP altogether.

TECHNICAL FIELD

This disclosure relates generally to the field of wirelesscommunication, and more particularly to implementing location awaresteering using fine timing measurement (FTM) frames in a wireless localarea network (WLAN).

DESCRIPTION OF THE RELATED TECHNOLOGY

A wireless local area network (WLAN) may be formed by one or morewireless access points (APs) that provide a shared wirelesscommunication medium for use by multiple client devices, which also maybe referred to as wireless stations (STAs). The basic building block ofa WLAN conforming to the Institute of Electrical and ElectronicsEngineers (IEEE) 802.11 family of standards is a Basic Service Set(BSS), which is managed by an AP. Each BSS is identified by a serviceset identifier (SSID) that is advertised by the AP. An AP periodicallybroadcasts beacon frames to enable other STAs within wireless range ofthe AP to establish or maintain a communication link with the WLAN.

A WLAN may include two or more APs. In the WLAN, a STA may wirelesslyassociate with a first AP to obtain wireless access to other devices ornetworks. The STA may remain associated with the first AP while withinan effect range of the first AP. As the STA moves outside the coveragearea of the first AP, the first AP may steer the STA to associate with asecond AP. Thus, the STA may seamlessly associate with the second APwithout losing service.

SUMMARY

The systems, methods, and devices of this disclosure each have severalinnovative aspects, no single one of which is solely responsible for thedesirable attributes disclosed herein.

One innovative aspect of the subject matter described in this disclosurecan be implemented in a method for wireless communication performed byan apparatus of a first access point (AP) in a wireless local areanetwork (WLAN). The method may include determining whether a WLAN deviceis capable of exchanging fine timing management (FTM) frames. The methodmay include, in response to determining the WLAN device is capable ofexchanging FTM frames, determining a first distance from the first AP tothe WLAN device based, at least in part, on the FTM frames exchangedwith the WLAN device, and obtaining an indication of a second distancebetween a second AP and the WLAN device. The method may include, inresponse to determining the WLAN device is capable of exchanging FTMframes, determining a location of the WLAN device based, at least inpart, on the first distance and the second distance, and steering theWLAN device to the second AP based, at least in part, on the location ofthe WLAN device.

In some aspects, the location may be a relative location of the WLANdevice with respect to the first AP and the second AP.

In some aspects, the method may include determining a signal strength ofa signal received from the WLAN device, and determining that the signalstrength is less than a signal strength threshold. The method ofdetermining whether a WLAN device is capable of exchanging FTM framesmay be in response to determining that the signal strength is less thana signal strength threshold.

In some aspects, the method of determining whether a WLAN device iscapable of exchanging FTM frames may include obtaining, from the WLANdevice, a capabilities element indicating the WLAN device is capable ofexchanging FTM frames.

In some aspects, the method of determining the first distance is based,at least in part, on FTM frames exchanged with the WLAN device mayinclude outputting the FTM frames for transmission to the WLAN device,and obtaining FTM acknowledgements (ACKs) associated with the FTM framesfrom the WLAN device. Determining the first distance is based, at leastin part, on FTM frames exchanged with the WLAN device also may includedetermining a round-trip time (RTT) based, at least in part, on the FTMframes and the FTM ACKs, and determining the first distance based, atleast in part, on the RTT.

In some aspects, the method of steering the WLAN device may includeselecting steering information based, at least in part, on the locationof the WLAN device, where the steering information indicates whether tosteer the WLAN device based, at least in part, on the location. Themethod may include determining to steer the WLAN device to the second APbased, at least in part, on the steering information.

In some aspects, the method of obtaining the indication of the seconddistance may include receiving an FTM range report that indicates thesecond distance.

In some aspects, the method also may include outputting an FTM requestfor transmission to the WLAN device, obtaining an FTM ACK from the WLANdevice, and in response to obtaining the FTM acknowledgment, exchangingthe FTM frames with the WLAN device.

In some aspects, the method also may include obtaining, from the secondAP, distance information including the indication of the seconddistance.

In some aspects, the method also may include obtaining distanceinformation from other APs in the WLAN, the distance informationindicating other distances from the other APs to the WLAN device.

In some aspects, the method also may include determining a thirddistance from the first AP to the WLAN device based, at least in part,on additional FTM frames exchanged with the WLAN device, and steeringthe WLAN device from a first frequency band of the first AP to a secondfrequency band of the first AP based, at least in part, on the thirddistance.

In some aspects, the method also may include, after steering the WLANdevice, determining a signal strength of communications received fromthe WLAN device, determining that the signal strength is greater than asignal strength threshold, and updating steering information to indicatethe location and the signal strength.

Another innovative aspect of the subject matter described in thisdisclosure can be implemented in method for wireless communicationperformed by an apparatus of an AP in a WLAN. The method may includedetermining whether a WLAN device is capable of exchanging FTM frames.The method may include, in response to determining the WLAN device iscapable of exchanging the FTM frames, determining a distance from the APto the WLAN device based, at least in part, on FTM frames exchanged withthe WLAN device. The method also may include, in response to determiningthe WLAN device is capable of exchanging the FTM frames, steering theWLAN device from a first frequency band of the AP to a second frequencyband of the AP based, at least in part, on the distance.

In some aspects, the method also may include determining a signalstrength of a signal received from the WLAN device, and determining thatthe signal strength is less than a signal strength threshold, wheredetermining whether a WLAN device is capable of exchanging FTM frames isin response to determining that the signal strength is less than asignal strength threshold.

In some aspects, the method also may include determining the AP has awireless association with the WLAN device via the first frequency band,and determining that the WLAN device is outside a first range of thefirst frequency band of the AP based, at least in part, on the distance.

In some aspects, the method also may include determining the WLAN iswithin a second range of the second frequency band.

In some aspects, the method also may include outputting the FTM framesfor transmission to the WLAN device, and obtaining FTM ACKs from theWLAN device.

In some aspects, the method of steering the WLAN device may includeselecting steering information based, at least in part, on the distancefrom the AP to the WLAN device, and determining to steer the WLAN deviceto the second frequency band based, at least in part, on the steeringinformation.

In some aspects, the method also may include, after steering the WLANdevice, determining a signal strength of communications received fromthe WLAN device, determining that the signal strength is greater than asignal strength threshold, and updating steering information to indicatethe distance and the signal strength.

Another innovative aspect of the subject matter described in thisdisclosure can be performed by an apparatus of a first access point (AP)for wireless communication. The apparatus may include a processor thatmay be configured to determine whether a WLAN device of a WLAN iscapable of exchanging FTM frames. The processor may be configured to, inresponse to a determination that the WLAN device is capable ofexchanging the FTM frames, determine a first distance from the first APto the WLAN device based, at least in part, on FTM frames exchanged withthe WLAN device, obtain an indication of a second distance between asecond AP and the WLAN device, and determine a location of the WLANdevice based, at least in part, on the first distance and the seconddistance. The apparatus also may include an interface configured tooutput a message to steer the WLAN device to the second AP based, atleast in part, on the location of the WLAN device.

In some aspects, the processor also may be configured to determine asignal strength of a signal received from the WLAN device, and determinethat the signal strength is less than a signal strength threshold. Thedetermination whether a WLAN device is capable of exchanging FTM framesmay be in response to determining that the signal strength is less thana signal strength threshold.

In some aspects, the processor is further configured to obtain theindication of the second distance from an FTM range report.

In some aspects, the interface may be further configured to output theFTM frames for transmission to the WLAN device and obtain FTM ACKs fromthe WLAN device. The processor may be further configured to determine anRTT based on the FTM frames and the FTM ACKs, and determine the firstdistance based on the RTT.

In some aspects, the processor may be further configured to selectsteering information based, at least in part, on the location of theWLAN device, where the steering information indicates whether to steerthe WLAN device based, at least in part, on the location. The processoralso may be configured to determine to steer the WLAN device to thesecond AP based, at least in part, on the steering information.

In some aspects, the processor may be further configured to determinethe location is outside a first coverage area of a first frequency bandof the first AP and within a second coverage area of a second frequencyband of the first AP, and steer the WLAN device from the first frequencyband of the first AP to the second frequency band of the first AP based,at least in part, on the location.

In some aspects, the processor may be further configured to determine athird distance from the first AP to the WLAN device based, at least inpart, on additional FTM frames exchanged with the WLAN device, and steerthe WLAN device from a first frequency band of the first AP to a secondfrequency band of the first AP based, at least in part, on the thirddistance.

Another innovative aspect of the subject matter described in thisdisclosure can be performed by an apparatus for wireless communicationof an access point (AP). The apparatus may include a processorconfigured to determine whether a WLAN device of a WLAN is capable ofexchanging FTM frames. The processor also may be configured to, inresponse to a determination that the WLAN device is capable ofexchanging the FTM frames, determine a distance from the AP to the WLANdevice based, at least in part, FTM frames exchanged with the WLANdevice, and steer the WLAN device from a first frequency band of the APto a second frequency band of the AP based, at least in part, on thedistance.

In some aspects, the processor may be further configured to determine asignal strength of a signal received from the WLAN device, and determinethat the signal strength is less than a signal strength threshold. Thedetermination whether a WLAN device is capable of exchanging FTM framesmay be in response to determining that the signal strength is less thana signal strength threshold.

In some aspects, the processor may be further configured to determinethe AP has a wireless association with the WLAN device via the firstfrequency band, and determine that the WLAN device is outside a firstcoverage area of the first frequency band of the AP based, at least inpart, on the distance.

In some aspects, the processor may be further configured to selectsteering information based, at least in part, on the distance of theWLAN device, and determine to steer the WLAN device to the secondfrequency band based, at least in part, on the steering information.

Another innovative aspect of the subject matter described in thisdisclosure can be implemented in a method for wireless communication ina WLAN performed by an apparatus of a first WLAN device. The method mayinclude determining a first distance from the first WLAN device to asecond WLAN device based, at least in part, on FTM frames exchanged withthe second WLAN device. The method may include determining whether thefirst WLAN device is located within a distance range of the second WLANdevice based, at least in part, on the first distance. The method mayinclude determining a signal strength associated with the second WLANdevice in response to the second WLAN device being within the distancerange. The method may include comparing the signal strength to one ormore signal strength thresholds. The method also may include providing afine placement indicator based on the comparison.

In some aspects, the method of comparing the signal strength to one ormore signal strength thresholds may include determining that the signalstrength is less than a first signal strength threshold of the one ormore signal strength thresholds. The first signal strength threshold mayindicate a minimum signal strength for the distance range.

In some aspects, the method of providing the fine placement indicatormay include providing a fine placement indicator indicating to move thefirst WLAN device nearer to the second WLAN device, in response todetermining that the signal strength is less than the first signalstrength threshold.

In some aspects, the method of comparing the signal strength to one ormore signal strength thresholds may include determining that the signalstrength is greater than a second signal strength threshold of the oneor more signal strength thresholds, the second signal strength thresholdindicating a maximum signal strength for the distance range.

In some aspects, the method of providing the fine placement indicatormay include providing the fine placement indicator indicating to movethe first WLAN device farther from the second WLAN device, in responseto determining that the signal strength is greater than the secondsignal strength threshold.

In some aspects, the method of comparing the signal strength to one ormore signal strength thresholds may include determining that the signalstrength is greater than or equal to a first signal strength thresholdof the one or more signal strength thresholds, the first signal strengththreshold indicating a minimum signal strength for the distance range.The comparing the signal strength to one or more signal strengththresholds also may include determining that the signal strength is lessthan or equal to a second signal strength threshold of the one or moresignal strength thresholds, the second signal strength thresholdindicating a maximum signal strength for the distance range.

In some aspects, the method of providing the fine placement indicatormay include providing the fine placement indicator indicating the firstWLAN device to remain at a current location, in response to determiningthat the signal strength is greater than or equal to the first signalstrength threshold and the signal strength is less than or equal to thesecond signal strength threshold.

In some aspects, the method may include determining one or moreadditional signal strengths associated with the second WLAN device inresponse to providing the fine placement indicator indicating the firstWLAN device to remain at a current location. The method also may includeupdating distance information based on the one or more additional signalstrengths.

In some aspects, the method may include determining, in response to thesecond WLAN device not being located within the distance range of thefirst WLAN device, whether the first distance is greater than thedistance range. The method also may include providing a coarse placementindicator to move the first WLAN device nearer to the second WLAN devicein response to determining the first distance is greater than thedistance range.

In some aspects, the method may include determining, in response to thefirst WLAN device not being located within the distance range of thesecond WLAN device, whether the first distance is less than the distancerange. The method also may include providing a coarse placementindicator to move the first WLAN device farther from the second WLANdevice in response to determining the first distance is less than thedistance range.

In some aspects, the method may include providing, in response to thefirst WLAN device being located within the distance range of the secondWLAN device, a coarse placement indicator indicating the first WLANdevice to remain at a current location in response to determining thefirst distance is within the distance range.

In some aspects, the method of determining the first distance from thefirst WLAN device to the second WLAN device based, at least in part, onFTM frames exchanged with the second WLAN device may include outputtinga first FTM frame for transmission to the second WLAN device. The methodmay include obtaining a second FTM frame from the second WLAN device,and determining a RTT based on the first FTM frame and the second FTMframe. The method also may include determining the first distance basedon the RTT.

In some aspects, the method of determining the signal strengthassociated with the second WLAN device may include determining areceived signal strength indicator (RSSI) from signals received from thesecond WLAN device.

In some aspects, the distance range may include a range of distancesbetween the first WLAN device and the second WLAN device.

Another innovative aspect of the subject matter described in thisdisclosure can be implemented in a method of wireless communication in aWLAN performed by an apparatus of a first WLAN device. The method mayinclude determining a first distance from the first WLAN device to asecond WLAN device based, at least in part, on FTM frames exchanged withthe second WLAN device. The method may include determining whether thefirst WLAN device is located within a distance range of the second WLANdevice based, at least in part, on the first distance. The method mayinclude determining channel state information (CSI) associated with thesecond WLAN device in response to the second WLAN device being withinthe distance range. The method may include comparing the CSI to one ormore CSI thresholds. The method may include providing a fine placementindicator based on the comparison.

In some aspects, the method of comparing the CSI to one or more CSIthresholds may include determining that the CSI is less than a first CSIthreshold of the one or more CSI thresholds. The first CSI threshold mayindicate one or more of scattering, fading and power decay over distancefor the distance range.

In some aspects, the method of providing the fine placement indicatorincludes providing the fine placement indicator indicating to move thefirst WLAN device nearer to the second WLAN device, in response todetermining that the CSI is less than the first CSI threshold.

In some aspects, the method of comparing the CSI to one or more CSIthresholds may include determining that the CSI is greater than a secondCSI threshold of the one or more CSI thresholds. The second CSIthreshold may indicate one or more of scattering, fading and power decayover distance for the distance range.

In some aspects, the method of providing the fine placement indicatormay include providing the fine placement indicator indicating to movethe first WLAN device farther from the second WLAN device, in responseto determining that the CSI is greater than the second CSI threshold.

In some aspects, the method of comparing the CSI to one or more CSIthresholds may include determining that the CSI is greater than or equalto a first CSI threshold of the one or more CSI thresholds. The firstCSI threshold may indicate a minimum CSI for the distance range. Themethod also may include determining that the CSI is less than or equalto a second CSI threshold of the one or more CSI thresholds. The secondCSI threshold may indicate a maximum CSI for the distance range.

In some aspects, the method of providing the fine placement indicatormay include providing the fine placement indicator indicating the firstWLAN device to remain at a current location, in response to determiningthat the CSI is greater than or equal to the first CSI threshold and theCSI is less than or equal to the second CSI threshold.

Another innovative aspect of the subject matter described in thisdisclosure can be performed by an apparatus of a first WLAN device forwireless communication. The apparatus may include one or more interfacesfor communicating via a WLAN. The apparatus may include one or moreprocessors that may be configured to determine a first distance from thefirst WLAN device to a second WLAN device based, at least in part, onFTM frames exchanged with the second WLAN device via the one or moreinterfaces. The one or more processors may be configured to determinewhether the first WLAN device is located within a distance range of thesecond WLAN device based, at least in part, on the first distance. Theone or more processors also may be configured to determine a signalstrength associated with the second WLAN device in response to thesecond WLAN device being within the distance range and compare thesignal strength to one or more signal strength thresholds. The one ormore processors also may be configured to output a fine placementindicator based on the comparison.

In some aspects, the one or more processors may be configured to comparethe signal strength to one or more signal strength thresholds, and theone or more processors may be configured to determine that the signalstrength is less than a first signal strength threshold of the one ormore signal strength thresholds. The first signal strength threshold mayindicate a minimum signal strength for the distance range.

In some aspects, the one or more processors may be configured to providethe fine placement indicator, and the one or more processors may beconfigured to provide, in response to a determination that the signalstrength is less than the first signal strength threshold, the fineplacement indicator indicating to move the first WLAN device nearer tothe second WLAN device.

In some aspects, the one or more processors may be configured to comparethe signal strength to one or more signal strength thresholds, and theone or more processors may be configured to determine that the signalstrength is greater than a second signal strength threshold of the oneor more signal strength thresholds. The second signal strength thresholdmay indicate a maximum signal strength for the distance range.

In some aspects, the one or more processors may be configured to providethe fine placement indicator, and the one or more processors may beconfigured to provide the fine placement indicator indicating to movethe first WLAN device farther from the second WLAN device, in responseto a determination that the signal strength is greater than the secondsignal strength threshold.

In some aspects, the one or more processors may be configured to comparethe signal strength to one or more signal strength thresholds, and theone or more processors may be configured to determine that the signalstrength is greater than or equal to a first signal strength thresholdof the one or more signal strength thresholds, the first signal strengththreshold indicating a minimum signal strength for the distance range.The one or more processors may be configured to determine that thesignal strength is less than or equal to a second signal strengththreshold of the one or more signal strength thresholds. The secondsignal strength threshold may indicate a maximum signal strength for thedistance range.

In some aspects, the one or more processors may be configured to providethe fine placement indicator, and the one or more processors may beconfigured to provide the fine placement indicator indicating the firstWLAN device to remain at a current location, in response to adetermination that the signal strength is greater than or equal to thefirst signal strength threshold and the signal strength is less than orequal to the second signal strength threshold.

Another innovative aspect of the subject matter described in thisdisclosure can be performed by a wireless communication apparatus of afirst WLAN device for wireless communication. The wireless communicationapparatus of a first WLAN may include one or more interfaces forcommunicating via a WLAN and one or more processors. The apparatus mayinclude one or more processors that may be configured to determine afirst distance from the first WLAN device to a second WLAN device based,at least in part, on FTM frames exchanged with the second WLAN devicevia the one or more interfaces. The one or more processors may beconfigured to determine whether the first WLAN device is located withina distance range of the second WLAN device based, at least in part, onthe first distance, and determine CSI associated with the second WLANdevice in response to the second WLAN device being within the distancerange. The one or more processors may be configured to compare the CSIto one or more CSI thresholds and output a fine placement indicatorbased on the comparison.

In some aspects, the CSI may include receiver CSI (CSIR) and transmitterCSI (CSIT), and the one or more processors may be configured todetermine a difference between CSIT and CSIR. The comparison of the CSIto one or more CSI thresholds may include comparing the differencebetween the CSIT and CSIR to the one or more CSI thresholds.

Another innovative aspect of the subject matter described in thisdisclosure can be implemented as a computer-readable medium havingstored therein instructions which, when executed by a processor, causesthe processor to perform any one of the above-mentioned methods.

Another innovative aspect of the subject matter described in thisdisclosure can be implemented as a system having means for implementingany one of the above-mentioned methods.

Details of one or more aspects of the subject matter described in thisdisclosure are set forth in the accompanying drawings and thedescription below. Other features, aspects, and advantages will becomeapparent from the description, the drawings, and the claims. Note thatthe relative dimensions of the following figures may not be drawn toscale.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a system diagram of an example wireless communicationnetwork.

FIG. 2 shows a timing diagram illustrating an example process forperforming a ranging operation.

FIG. 3 shows a system diagram of an example wireless local area network(WLAN) including an access point (AP) configured to perform locationaware steering based on timing information obtained from a station(STA).

FIG. 4 shows a system diagram of an example WLAN including an APconfigured to steer a STA from a first frequency band of the AP to asecond frequency band of the AP.

FIG. 5 shows a system diagram of an example WLAN including APs thatperform steering operations in response to signal information.

FIG. 6 depicts a process illustrating example operations performed by anapparatus of an AP for location aware steering.

FIG. 7 depicts a process illustrating example operations performed by anapparatus of an AP for location aware band steering.

FIG. 8 depicts a process illustrating example operations for performinglocation aware steering with a fine timing measurement (FTM) capableSTA.

FIG. 9 depicts a process illustrating example operations for performinglocation aware steering in WLANs that include FTM-capable STAs andFTM-incapable STAs.

FIG. 10 shows a system diagram of an example WLAN including an REconfigured to perform operations for placing the RE based on timinginformation obtained from an AP.

FIG. 11 shows a system diagram of an example WLAN including an REconfigured to perform operations for fine placement based on signalstrength information obtained from an AP.

FIG. 12 depicts a process illustrating example operations performed byan apparatus of a first WLAN device for using timing information toplace an RE in an environment.

FIG. 13 depicts a process illustrating example operations performed byan apparatus of a first WLAN device for using timing information toplace an RE in an environment.

FIG. 14 depicts a process illustrating example operations for coarseplacement of an RE in a WLAN that may have an FTM-capable AP.

FIG. 15 depicts example operations of a process for coarse and fineplacement of an RE in a WLAN that includes one or more FTM-capable APs.

FIG. 16 illustrates additional example operations of the process forcoarse and fine placement of an RE in a WLAN that includes one or moreFTM-capable APs.

FIG. 17 depicts example operations of a process or fine placement of anRE in a WLAN using channel state information (CSI).

FIG. 18 shows a block diagram of an example wireless communicationdevice.

FIG. 19A shows a block diagram of an example AP.

FIG. 19B shows a block diagram of an example STA.

FIG. 20 shows a block diagram of an example electronic device forimplementing aspects of this disclosure.

Like reference numbers and designations in the various drawings indicatelike elements.

DETAILED DESCRIPTION

The following description is directed to certain aspects for thepurposes of describing the innovative aspects of this disclosure.However, a person having ordinary skill in the art will readilyrecognize that the teachings herein can be applied in a multitude ofdifferent ways. The examples in this disclosure are based on wirelesslocal area network (WLAN) communication according to the Institute ofElectrical and Electronics Engineers (IEEE) 802.11 wireless standards.However, the described aspects may be implemented in any device, systemor network that is capable of transmitting and receiving radio frequency(RF) signals according to one or more of the IEEE 802.11 standards, theBluetooth® standard, code division multiple access (CDMA), frequencydivision multiple access (FDMA), time division multiple access (TDMA),Global System for Mobile communications (GSM), GSM/General Packet RadioService (GPRS), Enhanced Data GSM Environment (EDGE), TerrestrialTrunked Radio (TETRA), Wideband-CDMA (W-CDMA), Evolution Data Optimized(EV-DO), 1×EV-DO, EV-DO Rev A, EV-DO Rev B, High Speed Packet Access(HSPA), High Speed Downlink Packet Access (HSDPA), High Speed UplinkPacket Access (HSUPA), Evolved High Speed Packet Access (HSPA+), LongTerm Evolution (LTE), AMPS, or other known signals that are used tocommunicate within a wireless, cellular or internet of things (IoT)network, such as a system utilizing 3G, 4G, 5G, 6G, or furtherimplementations thereof, technology.

A wireless local area network (WLAN) in a home, apartment, business, orother type of environment may include two or more WLAN devices. A WLANmay include one or more access points (APs) and one or more stations(STAs). An AP is a type of STA that performs a distribution systemaccess function in the WLAN. For brevity, this disclosure refers to theWLAN devices which could either operate as an AP or a STA. An AP mayprovide wireless access to the STAs that are located in a coverage areaof the AP. The STAs may include various types of WLAN devices such asmobile phones, laptops, gaming systems (including virtual and augmentedreality systems (VR and AR, or collectively XR)), entertainment systems,smart appliances, wearables, and IoT devices. Some APs may be capable ofestablishing connectivity via more than one frequency band. For example,an AP may operate a first basic service set (BSS) on a first frequencyband (such as a 2.4 GHz frequency band) and a second BSS on a secondfrequency band (such as a 5 GHz frequency band). For brevity, the firstand second BSSs may be referred to as a first frequency band of the APand a second frequency band of the AP, respectively.

WLANs typically provide network connectivity throughout a physicalspace. As a STA moves into the space, it may receive signals from afirst AP such as a beacon frame and other signals. The STA may associatewith the first AP to establish connectivity to the WLAN. If the STAmoves outside a coverage area of the first AP, the signal strength ofthe signals received from the first AP may weaken. In some instances,the STA may be unaware of other APs, so it may remain associated withthe first AP despite the weak signals. In response to the weak signals,the STA may scan for a different AP that may provide stronger signals.For example, as the STA moves outside the coverage area of the first AP,the STA may enter the coverage area of a second AP. As the STA entersthe coverage area of the second AP, the first AP may attempt to steerthe STA to associate with the second AP.

Various aspects of this disclosure relate generally to AP steering orfrequency band steering based on a location of a STA. Some aspects morespecifically relate to the use of the fine timing measurement (FTM)procedure to determine the relative distance or location of the STA forsteering the STA from one AP to another AP. Some aspects relate to usingthe FTM procedure to determine the relative distance or location of theSTA for steering the STA from a first frequency band of an AP to asecond frequency band of that AP. In some implementations, an AP maydetermine the location of the STA based on timing information and maysteer the STA based on the location. To obtain the round trip timing(RTT) information, the AP may exchange FTM frames with the STA. The APmay determine a distance between itself and the STA based on the RTTinformation. The AP also may obtain distance information from other APs,where the distance information may include a distance between another APand the STA. Using the distance between itself and the STA andadditional distance information (such as a distance between another APand the STA), the AP may determine a location of the STA and steer theWLAN device based on its location. The AP may steer the WLAN device to adifferent frequency band of the AP or to different AP.

To facilitate steering, WLAN devices typically exchange signalinformation such as beacon measurement reports (defined in IEEE 802.11k)and received signal strength indicators (RSSI) measurements. Forexample, an AP may request a beacon measurement report from a STA, andthe STA may provide the beacon measurement report to the AP. The beaconmeasurement report may include signal strength information of one ormore beacon frames obtained from one or more APs of the WLAN. Theexchange of the beacon measurement report and other signal informationusing existing techniques may not be instantaneous, and in someinstances beacon reports may not be available. Thus, the steeringprocess may be delayed or may not occur. For example, although the APsmay periodically request beacon measurement reports, the STAs may notrespond to the requests. For example, the STA may not receive therequest from the AP due to interference in the WLAN and thus may notrespond to the AP. As another example, the STA may delay responding tothe request due to network congestion. Hence, the APs may postpone theirsteering processes until the APs receive the beacon measurement reports.In some instances, postponing the steering process causes the STA toremain connected to the first AP even when the STA has moved into thecoverage area of the second AP which could have served the STA betterthan the first AP. In some instances, steering delays cause APs to missopportunities for band steering and network load balancing. For example,some APs initiate steering when an RSSI measurement for a STA is lessthan a signal strength threshold. As the STA moves away from the AP,RSSI updates may be delayed because of communication problems related tolow signal strength. Delayed RSSI updates may cause the AP to miss anopportunity to steer the STA to another AP. Delayed RSSI updates alsomay cause the AP to miss an opportunity for steering the STA from afirst frequency band of the AP to a second frequency band of the AP.While the AP is waiting for the RSSI update, the STA may associate witha different AP. As an AP misses band steering opportunities, other APsin the WLAN may become overloaded.

Fine timing measurement (FTM) is a protocol that was introduced in IEEE802.11-2016 (which incorporated IEEE 802.11mc). WLAN devices mayexchange FTM frames and determine RTT by using time of departure (TOD)and time of arrival (TOA) timestamps captured during frame exchange. RTTinformation may include the TOD and TOA timestamps. Based on the RTTinformation, a WLAN device may measure an RTT relative to another WLANdevice. The WLAN device may multiply the RTT by 0.5 and an approximatespeed of light in the wireless medium to determine a distance betweenthe WLAN devices. The WLAN device may repeat the process with other WLANdevices to determine relative distances of the other WLAN devices or todetermine its location based on the relative distances to the other WLANdevices and their known locations.

In some implementations, an AP may determine the location of a STA basedon RTT information and may steer the STA based on the location. In someimplementations, an AP may exchange FTM frames with a STA to obtain RTTinformation that indicates a distance from the AP to the STA. The APalso may obtain distance information from other APs in the WLAN. Usingthe distance to the STA and the additional distance information, the APmay determine a location of the STA and steer the STA based on thelocation of the STA relative to the AP or to another AP.

In some implementations, a first AP may determine a first distance fromitself to a STA based on RTT information. For example, the first AP mayexchange FTM frames with the STA. The FTM frames may include RTTinformation indicating an RTT of communications between the AP and STA.Using the RTT, the AP may determine the first distance from the AP tothe STA. In some implementations, the first AP also may determine asecond distance from a second AP to the STA. For example, the first APmay obtain distance information from a second AP, where the distanceinformation includes the second distance—the distance from the STA tothe second AP. As another example, the first AP may obtain the distanceinformation in an FTM range report received from the second AP or anysuitable STA. In some implementations, the first AP may determine alocation of the STA based on the first and second distances. The firstAP may determine whether to steer the STA based on the location of theSTA. For example, the first AP may steer the STA to the second AP basedon the location of the STA, i.e., the STA may be more proximate to thesecond AP, or the STA may be capable of receiving signals with higherrelative strength based on its location.

In some implementations, the first AP may steer the STA to a differentfrequency band. For example, the first AP may steer the STA from asecond frequency band of the AP to a first frequency band of the APbased on the location of the STA. As the STA enters the coverage area ofthe first frequency band, the AP may steer the STA from the secondfrequency band to the first frequency band. For example, the firstfrequency band of the AP may have a greater coverage area compared tothe coverage area of the second frequency band of the AP. Thus, the APmay steer the STA to the first frequency band when the STA moves to afurther distance from the AP.

In some implementations, the first AP may access steering informationthat indicates whether to steer the STA based on its location. Dependingon the location of the STA, the steering information may direct thefirst AP not to steer the STA, to steer the STA to the second AP, or tosteer the STA to a different frequency band of the first AP, asdescribed further herein. For example, the steering information mayindicate a set of steering decisions for corresponding locations. Insome implementations, the steering information may include otherinformation, such as target APs to which the STA will be steered,distance information related to other APs, location information relatedto other APs, signal information related to other APs, or any otherinformation suitable to provide a basis for determining whether to steera WLAN device.

Some STAs may not support the FTM feature specified in IEEE 802.11-2016and thus may not support obtaining or exchanging FTM frames. Hence, insome implementations, an AP may determine whether a STA is capable ofexchanging FTM frames. In some implementations, during association, theAP may receive one or more elements indicating whether the STA iscapable of obtaining or exchanging FTM frames. For example, duringassociation, the AP may receive an Extended Capabilities element inwhich a field indicates the STA is capable of acting as an FTMresponder. If the STA is capable of acting as an FTM responder, the STAis FTM-capable. In some implementations, the AP may receive acapabilities element indicating the STA can provide range reportsindicating ranges between the STA and other APs, where the ranges aredetermined using the FTM procedure. A STA that is not FTM-capable alsomay be referred to as being FTM-incapable. An AP can determine locationsof FTM-capable STAs based on RTT information obtained from the STAs anddistance information from other APs. The AP may determine whether tosteer the STA based on the location of the STA.

In some implementations, steering may be triggered by weak signalstrength. For example, an AP may detect that an RSSI for a STA is lessthan a signal strength threshold. In response to determining that theRSSI for the STA is less than the signal strength threshold, the AP maydetermine whether the STA is FTM-capable and perform steering based onan FTM-derived location of the STA. Thus, the FTM and steering proceduremay be triggered based on a reduction or change in the RSSI of signalsreceived from the STA. The change in the RSSI may indicate, among otherthings, a change in the location of the STA relative to the AP. Thus,when the RSSI changes below the signal strength threshold, the AP mayinitiate the FTM to determine an updated location for the STA. If theSTA has moved to a new location, the AP may determine whether to steerthe STA based on the new location.

In some implementations, an AP can band steer FTM-capable STAs withoutinformation from other WLAN devices. For example, a STA may beassociated with a second frequency band of the AP. However, the firstfrequency band of the AP may support a greater distance compared to thesecond frequency band of the AP. The AP may exchange FTM packets withthe STA to determine a distance from the AP to the STA. Based on thedistance, the AP may steer the STA from a second frequency band of theAP to a first frequency band of the AP.

Particular implementations of the subject matter described in thisdisclosure can be implemented to realize one or more of the followingpotential advantages. Traditional techniques for steering may involveAPs sending information requests that go ignored by STAs. UnresponsiveSTAs may hinder the steering process. In some implementations, APs mayuse the FTM procedure to obtain information used in steering and achievebetter responsiveness from the STAs. In some implementations, an APusing RTT information derived from FTM frames to determine the locationof a STA may lead to faster steering decisions compared to existingsteering techniques that use signal information such as beaconmeasurement reports and RSSI. The AP making faster steering decisionsalso may result in fewer missed steering opportunities. Using RTTinformation also may result in the AP more accurately determining thelocation of the STA. As location accuracy increases, the WLAN may makebetter and more consistent steering decisions. Faster and more accuratesteering may lead to better STA performance and a better userexperience.

Providing wireless access throughout an environment may be challengingfor a single AP because various conditions may adversely affect wirelesssignals. As wireless signals travel over relatively long distances fromthe AP, the wireless signals may lose signal strength, which may degradethe wireless service being provided to STAs in the WLAN. In someenvironments, objects and materials may absorb, reflect, interfere withor otherwise adversely affect wireless signals. Adding one or more rangeextenders (REs) to a WLAN may increase signal strength in areasrelatively far away from APs and in areas where wireless signals areadversely affected by environmental conditions. REs may be additionalAPs in a WLAN that may extend coverage areas by receiving andretransmitting wireless signals between WLAN devices. For example, theREs may retransmit wireless signals from a central AP (CAP) to STAs inthe WLAN and vice versa. The CAP may be an AP that is connected to agateway. REs and other APs may extend the service of the CAP and can beconnected via wired or wireless links to the CAP.

The location of an RE may impact how well the RE increases the coveragearea or otherwise increases signal strength in the WLAN. The RE mayperform a process that assists in placing the RE at a suitable location.Traditional RE placement processes are based on the measured signalstrength of signals received from an AP. Based on the signal strength,the RE may provide feedback indicating whether the RE should be movednearer to an AP, farther from the AP, or remain at its current location.In some instances, there is not a simple relationship between signalstrength and distance from the AP. For example, environmental conditions(such as objects, walls, and other obstructions) may cause a first REnear the AP to have lower signal strength than a second RE that isfarther from the AP.

Various aspects of this disclosure relate generally to assisting with REplacement in an environment. Some aspects more specifically relate tousing both FTM frames and signal strength to assist in placing the RE ata suitable location within the environment. The RE may use FTM frames toguide aspects of a coarse placement of the RE and signal strength toguide a fine placement of the RE. FTM may enable the RE to measure anRTT from itself to the AP based on FTM frames it sends to and receivesfrom the AP. After measuring the RTT, the RE may determine a firstdistance from itself to the AP by multiplying the RTT by an approximatespeed of light in the wireless medium. By using FTM, the RE uses RTTinformation and not signal strength to determine the first distance. Byusing RTT information (such as FTM), the RE may determine the firstdistance to the AP without considering how environmental conditions mayaffect the signal strength.

Using a first distance from the RE to the AP, the RE may determinewhether it is located within an acceptable distance range from the APfor coarse placement of the RE. The acceptable distance range may be adistance range that extends the coverage area of the AP in the WLAN in asuitable manner, while maintaining a suitable signal strength. Hence, byusing the acceptable distance range, the RE may use RTT information tofind distances at which the signal strength and coverage area may besuitable during the coarse placement of the RE. The RE may provide acoarse placement indicator to indicate whether to move the RE nearer tothe AP, farther from the AP, or whether the RE is within the acceptabledistance range. The RE may repeat operations related to coarse placementuntil the RE is within the acceptable distance range of the AP.

If the RE is within the acceptable distance range, the RE may performoperations for a fine placement of the RE. In response to the REdetermining it is located within an acceptable distance range of the AP,the RE may determine a signal strength associated with the AP. Forexample, for fine placement of the RE, the RE may determine an RSSI fromsignals received from the AP.

The RE may compare the signal strength to one or more signal strengththresholds. The one or more signal strength thresholds may relate to oneor more signal strength ranges that indicate whether the RE should berelocated for fine placement of the RE. For example, a first signalstrength threshold may identify a minimum signal strength below whichthe RE should be moved nearer to the AP. A second signal strengththreshold may identify a maximum signal strength above which the REshould be moved farther from the AP. A range of values including theminimum signal strength and the maximum signal strength may indicate asignal strength range in which the RE should remain at its currentlocation. Hence, comparing the signal strength to one or more signalstrength thresholds may indicate whether the signal strength is toohigh, too low or within an acceptable range.

Based on a comparison of the signal strength to one or more signalstrength thresholds, the RE may provide a fine placement indicator toassist with fine placement of the RE in the environment. As noted, thecomparison may indicate whether the signal strength is too high, too lowor within a suitable signal strength range. The fine placement indicatormay relate to whether the signal strength is too high, too low or in asuitable signal strength range. For example, if the signal strength istoo high, the fine placement indicator may be an indication to move theRE farther from the AP. If the signal strength is too low, the fineplacement indicator may be an indication to move the RE nearer to theAP. If the signal strength is in a suitable signal strength range, thefine placement indicator may be an indication for the RE to remain atits current location. The fine placement indicator may include orotherwise cause presentation of any suitable audible or visibleindication (such as beeps, flashing lights, or text on a screen) to movethe RE in the environment.

Particular implementations of the subject matter described in thisdisclosure also can be implemented to realize one or more of thefollowing potential advantages. In some implementations, an RE using RTTinformation derived from FTM frames to determine a distance to an AP maylead to faster RE placement decisions compared to RE placementtechniques that use only signal information such as RSSI. The RE alsomay utilize signal information to provide more accurate placementguidance compared to traditional techniques for RE placement. The REalso may utilize channel state information to provide more accurate androbust placement guidance compared to traditional techniques for REplacement. The RE making faster, more accurate and more robust placementdecisions may create a better user experience by reducing time users arewaiting for guidance (such as audible or visual indicia) about where toplace the RE within an environment.

FIG. 1 shows a system diagram of an example wireless communicationnetwork 100. According to some aspects, the wireless communicationnetwork 100 can be an example of a wireless local area network (WLAN)such as a Wi-Fi network (and will hereinafter be referred to as WLAN100). For example, the WLAN 100 can be a network implementing at leastone of the IEEE 802.11 family of standards (such as that defined by theIEEE 802.11-2016 specification or amendments thereof including, but notlimited to, 802.11aa, 802.11ah, 802.11ad, 802.11aq, 802.11ay, 802.11ax,802.11az, 802.11ba and 802.11be). The WLAN 100 may include numerous WLANdevices such as an access point (AP) 102 and multiple stations (STAs)104 that have a wireless association with the AP 102. While only one AP102 is shown, the WLAN 100 also can include multiple APs 102. The IEEE802.11-2016 standard defines a STA as an addressable unit. An AP is anentity that contains at least one STA and provides access via a wirelessmedium (WM) for associated STAs to access a distribution service (suchas another network, not shown). Thus, an AP includes a STA and adistribution system access function (DSAF). In the example of FIG. 1 ,the AP 102 may be connected to a gateway device (not shown) whichprovides connectivity to the other network 140. The DSAF of the AP 102may provide access between the STAs 104 and another network 140. WhileAP 102 is described as an access point using an infrastructure mode, insome implementations, the AP 102 may be a traditional STA which isoperating as an AP. For example, the AP 102 may be a STA capable ofoperating in a peer-to-peer mode or independent mode. In some otherexamples, the AP 102 may be a software AP (SoftAP) operating on acomputer system.

Each of the STAs 104 also may be referred to as a mobile station (MS), amobile device, a mobile handset, a wireless handset, an access terminal(AT), a user equipment (UE), a subscriber station (SS), or a subscriberunit, among other possibilities. The STAs 104 may represent variousdevices such as mobile phones, personal digital assistant (PDAs), otherhandheld devices, netbooks, notebook computers, tablet computers,laptops, display devices (for example, TVs, computer monitors,navigation systems, among others), music or other audio or stereodevices, remote control devices (“remotes”), printers, kitchen or otherhousehold appliances, key fobs (for example, for passive keyless entryand start (PKES) systems), among other possibilities.

A single AP 102 and an associated set of STAs 104 may be referred to asa basic service set (BSS), which is managed by the respective AP 102.FIG. 1 additionally shows an example coverage area 108 of the AP 102,which may represent a basic service area (BSA) of the WLAN 100. The BSSmay be identified to users by a service set identifier (SSID), as wellas to other devices by a basic service set identifier (BSSID), which maybe a media access control (MAC) address of the AP 102. The AP 102periodically broadcasts beacon frames (“beacons”) including the BSSID toenable any STAs 104 within wireless range of the AP 102 to establish arespective communication link 106 (hereinafter also referred to as a“Wi-Fi link”), or to maintain a communication link 106, with the AP 102.For example, the beacons can include an identification of a primarychannel used by the respective AP 102 as well as a timingsynchronization function for establishing or maintaining timingsynchronization with the AP. The AP 102 may provide access to externalnetworks (such as the network 140) to various STAs 104 in the WLAN viarespective communication links 106. To establish a communication link106 with an AP 102, each of the STAs 104 is configured to performpassive or active scanning operations (“scans”) on frequency channels inone or more frequency bands (for example, the 2.4 GHz, 5 GHz, 6 GHz or60 GHz bands). To perform passive scanning, a STA 104 listens forbeacons, which are transmitted by respective APs 102 at a periodic timeinterval referred to as the target beacon transmission time (TBTT)(measured in time units (TUs) where one TU may be equal to 1024microseconds (μs)). To perform active scanning, a STA 104 generates andsequentially transmits probe requests on each channel to be scanned andlistens for probe responses from APs 102. Each STA 104 may be configuredto identify or select an AP 102 with which to associate based on thescanning information obtained through the passive or active scans, andto perform authentication and association operations to establish acommunication link 106 with the selected AP 102. The AP 102 may assignan association identifier (AID) to the STA 104 at the culmination of theassociation operations, which the AP 102 uses to track the STA 104.

As a result of the increasing ubiquity of wireless networks, a STA 104may have the opportunity to select one of many BSSs within range of theSTA or to select among multiple APs 102 that together form an extendedservice set (ESS) including multiple connected BSSs. An extended networkstation associated with the WLAN 100 may be connected to a wired orwireless distribution system that may allow multiple APs 102 to beconnected in such an ESS. As such, a STA 104 can be covered by more thanone AP 102 and can associate with different APs 102 at different timesfor different transmissions. Additionally, after association with an AP102, a STA 104 also may be configured to periodically scan itssurroundings to find a more suitable AP 102 with which to associate. Forexample, a STA 104 that is moving relative to its associated AP 102 mayperform a “roaming” scan to find another AP 102 having more desirablenetwork characteristics such as a greater received signal strengthindicator (RSSI) or a reduced traffic load.

In some cases, STAs 104 may form networks without APs 102 or otherequipment other than the STAs 104 themselves. One example of such anetwork is an ad hoc network (or wireless ad hoc network). Ad hocnetworks may alternatively be referred to as mesh networks orpeer-to-peer (P2P) networks. In some cases, ad hoc networks may beimplemented within a larger wireless network such as the WLAN 100. Insuch implementations, while the STAs 104 may be capable of communicatingwith each other through the AP 102 using communication links 106, STAs104 also can communicate directly with each other via direct wirelesslinks 107. Additionally, two STAs 104 may communicate via a directcommunication link 107 regardless of whether both STAs 104 areassociated with and served by the same AP 102. In such an ad hoc system,one or more of the STAs 104 may assume the role filled by the AP 102 ina BSS. Such a STA 104 may be referred to as a group owner (GO) and maycoordinate transmissions within the ad hoc network. Examples of directwireless links 107 include Wi-Fi Direct connections, connectionsestablished by using a Wi-Fi Tunneled Direct Link Setup (TDLS) link, andother P2P group connections.

The APs 102 and STAs 104 may function and communicate (via therespective communication links 106) according to the IEEE 802.11 familyof standards (such as that defined by the IEEE 802.11-2016 specificationor amendments thereof including, but not limited to, 802.11aa, 802.11ah,802.11aq, 802.11ad, 802.11ay, 802.11ax, 802.11az, 802.11ba and802.11be). These standards define the WLAN radio and baseband protocolsfor the PHY and medium access control (MAC) layers. The APs 102 and STAs104 transmit and receive wireless communications (hereinafter alsoreferred to as “Wi-Fi communications”) to and from one another in theform of physical layer convergence protocol (PLCP) protocol data units(PPDUs).

Each of the frequency bands may include multiple sub-bands or frequencychannels. For example, PPDUs conforming to the IEEE 802.11n, 802.11ac,802.11ax and 802.11be standard amendments may be transmitted over the2.4 and 5 GHz bands, each of which is divided into multiple 20 MHzchannels. As such, these PPDUs are transmitted over a physical channelhaving a minimum bandwidth of 20 MHz, but larger channels can be formedthrough channel bonding. For example, PPDUs conforming to the IEEE802.11n, 802.11ac, 802.11ax, and 802.11be standard amendments may betransmitted over physical channels having bandwidths of 40 MHz, 80 MHz,80+80 MHz, 160 MHz, 160+160 MHz or 320 MHz by bonding together two ormore 20 MHz channels, which can be contiguously allocated ornon-contiguously allocated. For example, IEEE 802.11n describes the useof up to 2 channels (for a combined 40 MHz bandwidth) and defined a HighThroughput (HT) transmission format. IEEE 802.11ac describes the use ofup to 8 channels (for a maximum combined 160 MHz bandwidth) and defineda Very High Throughput (VHT) transmission format. IEEE 802.11ax alsosupports up to a combined 160 MHz bandwidth (which may be a combinationof up to 8 channels of 20 MHz width each). IEEE 802.11be may support upto a combined 320 MHz bandwidth (which may be a combination of up to 16channels of 20 MHz width each).

The APs 102 and STAs 104 in the WLAN 100 may transmit PPDUs over anunlicensed spectrum, which may be a portion of spectrum that includesfrequency bands traditionally used by Wi-Fi technology, such as the 2.4GHz band, the 5 GHz band, the 60 GHz band, and the 900 MHz band. Someimplementations of the APs 102 and STAs 104 described herein also maycommunicate in other frequency bands, such as the 6 GHz band, which maysupport both licensed and unlicensed communications. The APs 102 andSTAs 104 also can be configured to communicate over other frequencybands such as shared licensed frequency bands, where multiple operatorsmay have a license to operate in the same or overlapping frequency bandor bands.

Each PPDU is a composite structure that includes a PHY preamble, a PHYheader, and a payload in the form of a PLCP service data unit (PSDU).For example, the PSDU may include the PHY preamble and header (which maybe referred to as PLCP preamble and header) as well as one or more MACprotocol data units (MPDUs). The information provided in the PHYpreamble and header may be used by a receiving device to decode thesubsequent data in the PSDU. In instances in which PPDUs are transmittedover a bonded channel, the preamble and header fields may be duplicatedand transmitted in each of the multiple component channels. The PHYpreamble may be used for packet detection, automatic gain control andchannel estimation, among other uses. The format of, coding of, andinformation provided in the PHY header is based on the particular IEEE802.11 protocol to be used to transmit the payload, and typicallyincludes signaling fields (such as SIG-A and SIG-B fields) that includeBSS and addressing information, such as a BSS color and a STA ID.

Aspects of transmissions may vary based on a distance between atransmitter (for example, an AP 102 or a STA 104) and a receiver (forexample, another AP 102 or STA 104). Wireless communication devices maygenerally benefit from having information regarding the location orproximities of the various STAs 104 within the coverage area. In someexamples, relevant distances may be computed using RTT-based rangingprocedures. Additionally, in some implementations, APs 102 and STAs 104may be configured to perform ranging operations. Each ranging operationmay involve an exchange of FTM frames (such as those defined in the IEEE802.11mc specification or revisions or updates thereof).

FIG. 2 shows a timing diagram illustrating an example process forperforming a ranging operation 200. The process for the rangingoperation 200 may be cooperatively performed by two wireless devices 202a and 202 b, which may each be an example of an AP 102 or a STA 104.

The wireless devices 202 a and 202 b may exchange FTM messages as partof a ranging operation 200. The ranging operation 200 may begin with thefirst wireless device 202 a transmitting an initial FTM range requestframe 204 at time t1,0. In some implementations, the second wirelessdevice 202 b may respond to the FTM range request 204 withinapproximately 10 milliseconds (+/−3 ms) of receiving it. Responsive tosuccessfully receiving the FTM range request frame 204 at time t2,0, thesecond wireless device 202 b may respond by transmitting a first ACK 206at time t3,0, which the first wireless device 202 a may receive at timet4,0. The first wireless device 202 a and the second wireless device 202b may exchange one or more FTM bursts, which may each include multipleexchanges of FTM action frames (hereinafter simply “FTM frames”) andcorresponding ACKs. One or more of the FTM range request frames 204 andthe FTM action frames (hereinafter simply “FTM frames”) may include FTMparameters specifying various characteristics of the ranging operation200.

In the example shown in FIG. 2 , in a first exchange, beginning at timet1,1, the second wireless device 202 b may transmit a first FTM frame208. The second wireless device 202 b may record the time t1,1 as theTOD of the first FTM frame 208. The first wireless device 202 a mayreceive the first FTM frame 208 at time t2,1 and may transmit a firstacknowledgement frame (ACK) 210 to the second wireless device 202 b attime t3,1. The first wireless device 202 a may record the time t2,1 asthe TOA of the first FTM frame 208, and the time t3,1 as the TOD of thefirst ACK 210. The second wireless device 202 b may receive the firstACK 210 at time t4,1 and may record the time t4,1 as the TOA of thefirst ACK 210.

Similarly, in a second exchange, beginning at time t1,2, the secondwireless device 202 b may transmit a second FTM frame 212. The secondFTM frame 212 may include a first field indicating the TOD of the firstFTM frame 208 and a second field indicating the TOA of the first ACK210. The first wireless device 202 a may receive the second FTM frame212 at time t2,2 and may transmit a second ACK 214 to the secondwireless device 202 b at time t3,2. The second wireless device 202 b mayreceive the second ACK 214 at time t4,2. Similarly, in a third exchange,beginning at time t1,3, the second wireless device 202 b may transmit athird FTM frame 216. The third FTM frame 216 may include a first fieldindicating the TOD of the second FTM frame 212 and a second fieldindicating the TOA of the second ACK 214. The first wireless device 202a may receive the third FTM frame 216 at time t2,3 and may transmit athird ACK 218 to the second wireless device 202 b at time t3,3. Thesecond wireless device 202 b may receive the third ACK 218 at time t4,3.

The first wireless device 202 a may determine a range indication basedon the TODs and TOAs described above. For example, in implementations orinstances in which an FTM burst includes four exchanges of FTM frames asdescribed above, the first wireless device 202 a may be configured todetermine a round trip time (RTT) between itself and the second wirelessdevice 202 b based on Equation 1 below.RTT=½((ΣL _(k=1) ² t _(4,k)−Σ_(k=1) ² t _(1,k))(Σ_(k=1) ² t_(3,k)−Σ_(k=1) ² t _(2,k)))  (1)

In some implementations, the range indication is the RTT. Additionallyor alternatively, in some implementations, the first wireless device 202a may determine an actual approximate distance between itself and thesecond wireless device 202 b, for example, by multiplying the RTT by 0.5and by an approximate speed of light in the wireless medium. In suchinstances, the range indication may additionally or alternativelyinclude the distance value. Additionally or alternatively, the rangeindication may include an indication as to whether the second wirelessdevice 202 b is within a proximity (for example, a service discoverythreshold) of the first wireless device 202 a based on the RTT. In someimplementations, the first wireless device 202 a may transmit the rangeindication to the second wireless device 202 b, for example, in a rangereport 224 at time t1,4, which the second wireless device receives attime t2,4.

As described previously, this disclosure includes some exampletechniques in which the FTM protocol may be used to determine a locationof a STA. An AP may determine whether to steer the STA to another AP orto another frequency band of the AP based on the location of the STA.

FIG. 3 shows a system diagram of an example WLAN including an APconfigured to perform location aware steering based on RTT informationobtained from a STA. The WLAN 300 shown in FIG. 3 is based on theexample WLAN 100 described in FIG. 1 . The WLAN 300 includes the APs 310and 312 and a STA 314. In various examples described herein, one or moreof the WLAN devices, such as the STA 314, may be referred to as STAs forsimplicity, regardless of whether the WLAN device is an AP or a non-APSTA. For example, the STA 314 may be either a non-AP STA or an AP.Furthermore, although not shown for simplicity, the WLAN 300 may includeone or more additional STAs, which may include one or more additionalAPs and one or more additional non-AP STAs. In some implementations, theWLAN 300 may be configured as a mesh network, which may include the AP310, the AP 312, and one or more additional APs. The APs 310 and 312 maybe connected to a gateway device (not shown) which provides connectivityto another network. The APs 310 and 312 may be example implementationsof the AP 102 of FIG. 1 or the AP 1902 of FIG. 19A. The STA 314 may bean example implementation of the STAs 104 of FIG. 1 or the STA 1904 ofFIG. 19B.

Each of the APs 310 and 312 may include a measurement unit 306. Themeasurement unit 306 may determine distances from the AP to STAs. Forexample, in the AP 310, the measurement unit 306 may determine adistance from the AP 310 to the STA 314. In some implementations, themeasurement unit 306 may determine distances based on signalinformation. For example, in AP 310, the measurement unit 306 may obtainsignal information, such as RSSIs and beacon measurement reports,associated with the STA 314. The measurement unit 306 may determine thedistance from the AP 310 to the STA 314 based on the signal information.In some implementations, the measurement unit 306 also may determinedistances based on RTT information. From example, in the AP 310, themeasurement unit 306 may determine a distance from the AP 310 to the STA314 based on RTT information derived from FTM frames exchanged with theSTA 314. The FTM frames may include timestamps that indicate an RTTbetween the AP 310 and the STA 314. Using the RTT, the measurement unit306 may determine the distance between the AP 310 and the STA 314. Themeasurement unit 306 also may obtain location information from the AP312. The location information may include a distance from the AP 312 tothe STA 314. The location information also may include a location of theSTA 314 relative to the AP 312. Using the distance from the AP 310 tothe STA 314 and the location information obtained from the AP 312, themeasurement unit 306 may determine a location of the STA 314. In someimplementations, the location may be relative to the AP 310. The AP 310may share location information about the STA 314 with other APs in theWLAN 300, such as the AP 312.

Each of the APs 310 and 312 also may include a steering unit 308. Thesteering unit 308 may include steering information 318 used in makingsteering decisions. In some implementations, the steering unit 308 maysteer STAs based on locations determined by the measurement unit 306 andthe steering information 318. The steering unit 308 may use a locationto access a steering decision in the steering information 318. In someimplementations, the steering information 318 may associate locationswith steering decisions such as “steer” or “not steer.” In someimplementations, the steering information indicates a target AP to whichthe STA will be steered (such as the AP 312). The steering unit 308 mayoperate a feedback loop that updates the steering information 318. Forexample, after steering a STA, the steering unit 308 may measure signalstrength at the STA to determine whether steering was effective. Thesteering unit 308 may update the steering information 318 based on thisdetermination. The steering information 318 can be implemented as a datastructure in a memory device. For example, in some implementations, thesteering information 318 may include a lookup table including steeringdecisions that are indexed by location or area. In some otherimplementations, the steering information 318 can be organized in anyother manner suitable for storing information and include anyinformation suitable for determining a steering decision based on alocation of the STA 314.

In some implementations, the STA 314 may begin at a first position 316in the coverage area of the AP 310. While in the coverage area of the AP310, the STA 314 has a wireless association 302 to the AP 310. Over atime period, the STA 314 may move closer to a coverage area of the AP312. Over that time period, the AP 310 may determine the location of theSTA 314 one or more times. To determine a location, the AP 310 mayexchange FTM frames with the STA 314. The FTM frames may include RTTinformation that may be used to determine an RTT between the AP 310 andthe STA 314. Based on the RTT, the AP 310 may determine a distance fromthe AP 310 to the STA 314. The AP 310 also may determine a distance fromthe STA 314 to the AP 312. For example, the AP 310 may obtain locationinformation that indicates the distance from the STA 314 to the AP 312via a measurement frame received from the AP 312. The AP 310 may use thedistance along with location information obtained from the AP 312 todetermine a location of the STA 314. In some implementations, thelocation may be relative to the AP 310. In some implementations, the AP310 may determine a relative location of the STA using two or moredistances to known locations, such as the respective distances from theSTA 314 to the AP 312 and the STA 314 to the AP 310. If there are one ortwo distances to known locations, the AP 310 may represent the locationof the STA 314 with a set of coordinates indicating points at which theSTA 314 may reside. If there are three or more distances to knownlocations (such as distance information relating to three or more APs),the AP 310 may use trilateration to determine a single pointrepresenting a location of the STA 314 relative to the AP 310. The AP310 may use the location of the STA 314 to determine whether to steerthe STA 314. The AP 310 may periodically repeat the process ofdetermining a location and determining whether to steer. Hence, over thetime period in which the STA 314 is moving nearer to the AP 312, the AP310 may determine one or more locations for the STA 314 and make one ormore steering decisions about the STA 314. In some implementations, theAP 310 may access steering information that indicates whether to steerthe STA 314 based on its location. Depending on the location of the STA314, the steering information may direct the AP 310 to steer the STA 314to the AP 312. After the AP 310 steers the STA 314 to the AP 312, theSTA 314 establishes a wireless association 304 with the AP 312.

Steering refers to any activity which causes the device to wirelesslyassociate with a second AP instead of maintaining the association with afirst AP. Steering also may be referred to as a re-association activity,move, transfer, relocate, transition, switch, re-position, handover, orthe like. There are various techniques which can be used to steer a STA314 to a particular AP or frequency band. For example, using IEEE802.11v or other protocols, the AP 310 may simply request the device tore-associate to the AP 312. An IEEE 802.11v configuration message mayinclude a list of one or more other APs (for example, including the AP312) as a suggestion to the STA 314 to re-associate to the AP 312.However, if the STA 314 does not support IEEE 802.11v protocols orchooses to ignore the suggestion, the AP 310 may use another techniqueto steer the STA 314. For example, the AP 310 may send a disassociationmessage to the STA 314 or the AP 310 may block traffic (at least oneincoming packet) for the STA 314 to force the STA 314 to re-associatewith the AP 312.

FIG. 4 shows a system diagram of an example WLAN including an APconfigured to steer a STA from a first frequency band of the AP to asecond frequency band of the AP. As described in FIG. 3 , the WLAN 300may include the AP 310, the AP 312, and the STA 314.

The AP 310 may support communications over a first frequency band and asecond frequency band. The first frequency band may include the 2.4 GHzband and the second frequency band may include the 5 GHz band. The firstfrequency band may have a coverage area represented by a first areawithin a circle 322. The second frequency band may have a coverage arearepresented by a second area within a circle 320.

Initially, the STA 314 may be within the coverage area of the firstfrequency band and may have a wireless association 402 to the AP 310over the first frequency band. As the STA 314 moves around theenvironment, the AP 310 may track movements of the STA 314. The AP 310may determine a distance from the AP 310 to the STA 314 based on RTTinformation included in FTM frames exchanged with the STA 314. The FTMframes may include timestamps that may be used to derive an RTT betweenthe AP 310 and the STA 314. Using the RTT, the AP 310 may determine thedistance from the AP 310 to the STA 314. The AP 310 can determinewhether to steer the STA 314 based on the steering information 318 (asshown in FIG. 3 ) and the distance from the AP 310 to the STA 314.Initially, the AP 310 may not steer the STA 314 because the STA 314 isconnected via the first frequency band and is located within itscoverage area. Over time, the AP 310 may track movements of the STA 314by repeating this process. As the STA 314 moves closer to the AP 310,the AP 310 may determine the STA 314 is within the coverage area of thesecond frequency band based on RTT information obtained from the STA314. In response, the AP 310 may steer the STA 314 from the firstfrequency band to the second frequency band, resulting in the wirelessassociation 404. As the AP 310 repeats the process of determiningdistances, the AP 310 may share the distances with the AP 312. Forexample, the AP 310 may transmit a management frame to the AP 312 toshare location information that indicates the distance from the AP 310to the STA 314.

FIG. 5 shows a system diagram of an example WLAN including APs thatperform steering operations in response to signal information. Asdescribed in FIG. 3 , the WLAN 300 may include the AP 310, the AP 312and the STA 314.

As shown in FIG. 5 , the AP 312 may have a coverage area inside thecircle 508. The AP 310 may have a coverage area inside the circle 506.The ranges define an area 510 in which the STA 314 may be in thecoverage area for both of the APs 310 and 312. A steering boundary 504represents a distance from the AP 310 at which signal strength for theSTA 314 may be less than a signal strength threshold. In someimplementations, a steering process may be triggered when the signalstrength is less than the signal strength threshold. For example, theSTA 314 may be initially connected to the AP 312 via a wirelessassociation 502. The AP 312 may monitor RSSI measurements to determinewhether signal strength is less than the signal strength threshold. TheAP 312 may determine an RSSI from one or more signals received from theSTA 314. The AP 312 may determine whether the RSSI indicates a signalstrength less than the signal strength threshold. As the STA 314 movesaway from the AP 312, the signal strength may decrease. If the STA 314moves past the steering boundary 504, the signal strength may drop belowthe signal strength threshold. In response to determining the signalstrength is less than the signal strength threshold, the AP 312 maydetermine a location of the STA 314 based on RTT information associatedwith the STA 314 and location information obtained from the AP 310. Forexample, the AP 312 may exchange FTM frames with the STA 314. The FTMframes may include RTT information that may be used to determine an RTTbetween the AP 312 and the STA 314. Based on the RTT, the AP 312 maydetermine a distance from the AP 312 to the STA 314. The AP 312 also maydetermine a distance from the STA 314 to the AP 310. For example, the AP312 may obtain location information that indicates the distance from theSTA 314 to the AP 310 via a measurement frame received from the AP 310.The AP 312 may determine whether to steer the STA 314 based on thelocation of the STA 314. The AP 312 may access steering information thatindicates whether to steer the STA based on its location. Depending onthe location of the STA, the steering information may direct the AP 312to steer the STA to the second AP. The AP 312 may steer the STA 314 tothe AP 310. After steering, the STA 314 establishes a wirelessassociation 512 with the AP 310. The AP 312 may share the distance fromthe AP 312 to the STA 314 and the location of the STA 314 with the AP310.

FIG. 6 depicts a process 600 illustrating example operations performedby an apparatus of an AP for location aware steering. The process 600may be performed by a wireless communication device such as the wirelesscommunication device 1800 or the electronic device 2000 described withreference to FIGS. 18 and 20 , respectively. In some implementations,the process 600 may be performed by a wireless communication deviceoperating as or within an AP, such as one of the APs 102, 310, 312 and1902 described with reference to FIGS. 1, 3, 4, 5 and 19A, respectively.

At block 610, an apparatus of a first AP in a WLAN may determine whethera WLAN device is capable of exchanging FTM frames.

At block 614, in response to determining the WLAN device is capable ofexchanging FTM frames, the apparatus of the first AP may continue theprocess 600 at block 618.

At block 618, the apparatus of the first AP may determine a firstdistance from the first AP to the WLAN device based, at least in part,on FTM frames exchanged with the WLAN device.

At block 620, the apparatus of the first AP may obtain a second distancefrom a second AP to the WLAN device.

At block 630, the apparatus of the first AP may determine a location ofthe WLAN device based, at least in part, on the first distance and thesecond distance.

At block 640, the apparatus of the first AP may steer the WLAN to theremote AP based, at least in part, on the location of the STA.

FIG. 7 depicts a process 700 illustrating example operations performedby an apparatus of an AP for location aware band steering. The process700 may be performed by a wireless communication device such as thewireless communication device 1800 or the electronic device 2000described with reference to FIGS. 18 and 20 , respectively. In someimplementations, the process 700 may be performed by a wirelesscommunication device operating as or within an AP, such as one of theAPs 102, 310, 312 and 1902 described with reference to FIGS. 1, 3, 4, 5and 19A, respectively.

At block 710, the apparatus of the AP in the WLAN may determine whethera WLAN device is capable of exchanging FTM frames.

At block 720, in response to determining the WLAN device is capable ofexchanging FTM frames, the process continues at block 730.

At block 730, the apparatus of the AP may determine a distance from theAP to a WLAN device of a WLAN based, at least in part, on FTM framesexchanged with the WLAN device.

At block 740, the apparatus of the AP may steer the WLAN device from asecond frequency band of the AP to a first frequency band of the APbased, at least in part, on the distance.

FIG. 8 depicts a process 800 illustrating example operations forperforming location aware steering with an FTM-capable STA. The process800 may be performed by a wireless communication device such as thewireless communication device 1800 or the electronic device 2000described with reference to FIGS. 18 and 20 , respectively. In someimplementations, the process 800 may be performed by a wirelesscommunication device operating as or within an AP, such as one of theAPs 102, 310, 312 and 1902 described with reference to FIGS. 1, 3, 4, 5and 19A, respectively. The description of the flowchart 800 will referto the AP 310 and other devices described with reference to FIG. 3 .

At block 810, the AP 310 may detect an FTM-capable STA 314. In someimplementations, the AP 310 may detect a probe request or othercommunication from the STA 314 indicating the STA 314 is FTM-capable. Insome instances, the AP 310 may receive a capabilities element includinga field that indicates the STA 314 FTM-capable. For example, the AP 310may receive an Extended Capabilities element in which a field indicatesthe STA 314 is capable of acting as an FTM responder. If the STA 314 iscapable of acting as an FTM responder, the STA 314 is FTM-capable. Insome implementations, all STAs in the WLAN 300 may be FTM-capable.

At block 820, the AP 310 may exchange FTM frames with the STA 314. Insome implementations, the AP 310 may output an FTM request fortransmission to the STA 314. The STA may return an FTM ACK. In responseto the FTM ACK, the AP 310 may exchange FTM frames with the STA 314. TheFTM frames may include timestamps or other timing information that maybe used to determine an RTT from the AP 310 to the STA 314.

At block 830, the AP 310 may determine a distance to the STA 314 basedon the FTM frames. In some implementations, the AP 310 may determine adistance to the STA 314 based on the RTT associated with the FTM frames.

At block 840, the AP 310 may obtain first location informationindicating a location of the STA 314 relative to other APs in the WLAN300. In some implementations, the AP 310 may obtain the first locationinformation from the AP 312 via management frames shared between the APs310 and 312. The location information may include a distance between theAP 312 and the STA 314, a location of the STA 314 relative to the AP312, distances between other APs (not shown in FIG. 3 ) in the WLAN 300,locations relative to the other APs, and any other suitable locationinformation.

At block 850, the AP 310 may determine a location of the STA 314 basedon the distance (determined at block 830) and the location information.In some implementations, the AP 310 may determine a location of the STA314 using two or more distances to known locations, such as therespective distances from the STA to the AP 312 and the AP 310. If thereare fewer than three distances, the AP 310 may represent the location ofthe STA with a set of coordinates indicating points at which the STA mayreside. If there are three or more distances (such as when the distanceinformation relates to three or more APs), the AP 310 may usetrilateration to determine a single point representing a location of theSTA 314. The operations may continue in parallel at block 860 and block870.

At block 860, the AP 310 may determine whether the location of the STA314 is suitable for steering. In some implementations, the AP 310 maymake this determination based on the steering information 318. In someimplementations, the steering information 318 may indicate steeringdecisions to be made at various locations. Using the location of the STA314 as an index into the steering information 318, the AP 310 may obtaina steering decision associated with the location. In someimplementations, the steering information 318 may include otherinformation, such as target APs to which the STA 314 will be steered,distance information related to WLAN devices, location informationrelated to WLAN devices, signal information related to WLAN devices andany other suitable information that may provide a basis for determiningwhether to steer a WLAN device. If the location is not suitable forsteering, operations continue at block 820. If the location is suitablefor steering, operations continue at block 880.

At block 880, the AP 310 may steer the STA 314. In some implementations,the AP 310 may steer the STA 314 to a target AP (such as the AP 312)indicated in the steering information 318.

At block 870, the AP 310 outputs second location information indicatingthe location of the STA 314 relative to the AP 310. The AP 312 and otherAPs in the WLAN 300 (not shown) may obtain the second locationinformation and use it to perform location aware steering.

FIG. 9 depicts a process 900 illustrating example operations forperforming location aware steering in WLANs that include FTM-capableSTAs and FTM-incapable STAs. The process 900 may be performed by awireless communication device such as the wireless communication device1800 or the electronic device 2000 described with reference to FIGS. 18and 20 , respectively. In some implementations, the process 900 may beperformed by a wireless communication device operating as or within anAP, such as one of the APs 102, 310, 312 and 1902 described withreference to FIGS. 1, 3, 4, 5, 19A and 20 , respectively. The followingdescription of the process 900 will refer to the AP 310 and otherdevices described with reference to FIG. 3 .

At block 901, the AP 310 may determine a signal strength for a STA 314.

At block 902, the AP 310 may determine whether the signal strength forthe STA 314 is less than a signal strength threshold. In someimplementations, the AP 310 may determine an RSSI from one or moresignals received from the STA 314, and may determine a signal strengthbased on the RSSI. In some implementations, the AP 310 also maydetermine whether other conditions are satisfied, such as whether anetwork load condition is satisfied. For example, the network loadcondition may be satisfied when a target AP for the steering operation(such as AP 312) is not overloaded. The network load condition may notbe satisfied when the target AP (such as AP 312) is overloaded. If thesignal strength is greater than or equal to the signal strengththreshold or the network load condition is not satisfied, the AP 310 maycontinue monitoring signal strength by looping back to block 902. If thesignal strength is less than a signal strength threshold or the networkload condition is satisfied, the operations may continue at block 904.

At block 904, the AP 310 may determine whether the STA is FTM-capable.In some implementations, the AP 310 may receive a capabilities elementincluding a field that indicates the STA 314 FTM-capable. For example,during association, the AP 310 may receive a capabilities elementindicating the STA is capable of acting as an FTM responder. If the STAis capable of acting as an FTM responder, the STA is FTM-capable. If theSTA 314 is FTM-capable, operations may continue at block 916. If the STAis not FTM-capable, operations may continue at block 908.

At block 908, the AP 310 may request, from the STA 314, informationindicating a signal strength with respect to the AP 310 and other APs inthe WLAN. In some implementations, the AP 310 may request a beaconmeasurement report that includes a received channel power indicator(RCPI) with respect to the AP 310 and other APs in the WLAN 300. The APalso may request other IEEE 802.11k reports (such as neighbor reports)or other information indicating signal strength with respect to the AP310 and other APs. IEEE 802.11k is an amendment to IEEE 802.11 standardfor radio resource management. It defines and exposes radio and networkinformation to facilitate the management and maintenance of a WLAN.

At block 910, the AP 310 may determine whether the STA responded to therequest for signal strength information. In some implementations, theSTA 314 may provide one or more beacon measurement reports including theRCPI with respect to the AP 310 and other APs in the WLAN 300. The STA314 may provide additional IEEE 802.11k information or any othersuitable information indicating signal strength with respect to APs inthe WLAN 300. If the STA 314 did not respond to the request for signalstrength information, operations may continue at block 908. If the STAresponded to the request for signal strength information, operations maycontinue at block 912.

At block 911, the AP 310 may be implemented to compare signal strengthreceived from the STA 314 to a signal strength of the STA 314 withrespect to other APs in the WLAN 300. In some implementations, the AP310 may compare RCPI with respect to itself and the STA 314 with one ormore RCPIs with respect to the STA 314 and other APs in the WLAN 300.

At block 912, the AP 310 may determine whether the difference in thesignal strengths is greater than a signal strength threshold. In someimplementations, the AP 310 may determine whether the difference inRCPIs is greater than a signal strength threshold. If the difference inthe signal strengths is greater than the signal strength threshold,operations may continue at block 914. If the difference in the signalstrengths is less than the signal strength threshold, operations maycontinue at block 902.

At block 914, the AP 310 may steer the STA 314. For STAs that areFTM-incapable, the AP 310 may steer the STA 314 to a target AP based onsignal information (such as RCPI).

Referring back to block 904, if the STA 314 is FTM-capable, theoperations may continue at block 916. At block 916, the AP 310 mayexchange FTM frames with the STA 314. In some implementations, the AP310 may output an FTM request for transmission to the STA 314. The STA314 may return an FTM ACK. In response to the FTM ACK, the AP 310 mayexchange FTM frames with the STA 314. The FTM frames may includetimestamps or other timing information that may be used to determine anRTT from the AP 310 to the STA 314.

At block 918, the AP 310 may determine a distance to the STA 314 basedon the FTM frames. In some implementations, the AP 310 may determine adistance to the STA 314 based on the RTT associated with the FTM frames.

At block 920, the AP 310 may obtain location information indicating alocation of the STA 314 relative to other APs in the WLAN 300. In someimplementations, the AP 310 may obtain the location information from theAP 312 via management frames shared between the APs 310 and 312. Thelocation information may include a distance between the AP 312 and theSTA 314, a location of the STA 314 relative to the AP 312, distancesbetween other APs (not shown in FIG. 2 ) in the WLAN 300, locationsrelative to the other APs, and any other suitable location information.

At block 922, the AP 310 may determine a location of the STA 314 basedon the distance (determined at block 918) and the location information.In some implementations, the AP 310 may determine a location of the STA314 using two or more distances to known locations, such as therespective distances from the STA 314 to the AP 312 and the AP 310. Ifthere are fewer than three distances, the AP 310 may represent thelocation of the STA 314 with a set of coordinates indicating points atwhich the STA 314 may reside. If there are three or more distances (suchas when the distance information relates to three or more APs), the AP310 may use trilateration to determine a single point representing alocation of the STA 314.

At block 924, the AP 310 may determine whether the location of the STA314 is suitable for steering. In some implementations, the AP 310 maymake this determination based on the steering information 318. In someimplementations, the steering information 318 may indicate steeringdecisions to be made at various locations. Using the location of the STA314 as an index into the steering information 318, the AP 310 may obtaina steering decision associated with the location. In someimplementations, the steering information 318 may include otherinformation, such as target APs to which the STA 314 will be steered,distance information related to WLAN devices, location informationrelated to WLAN devices, signal information related to WLAN devices andany other suitable information that may provide a basis for determiningwhether to steer a WLAN device. If the location is not suitable forsteering, operations continue at block 902. If the location is suitablefor steering, operations continue at block 914.

If the operations move to block 914 from block 924, the AP 310 may steerthe STA 314 to a target AP (such as the AP 312) indicated in thesteering information 318.

FIG. 10 shows a system diagram of an example WLAN including an REconfigured to perform operations for placing the RE based on RTTinformation obtained from an AP. The WLAN 1000 shown in FIG. 10 is basedon the example WLAN 100 described in FIG. 1 . The WLAN 1000 includes anRE 1010 and an AP 1002. Although not shown for simplicity, the WLAN 1000may include one or more STAs, which may include one or more additionalAPs and one or more additional non-AP STAs. In some implementations, theWLAN 1000 may be configured as a mesh network, which may include the AP1002, the RE 1010 and one or more additional APs. The AP 1002 may be acentral AP (CAP), where a CAP is an AP that is connected to a gatewaydevice (not shown) that provides connectivity to another network. An REmay be an AP that may extend a coverage area by receiving andretransmitting wireless signals between WLAN devices. An RE may extendthe service of the CAP and may be connected to the CAP via wired orwireless links. In some implementations, the RE 1010 may be an AP withinthe WLAN 1000 that may receive and retransmit wireless signals betweenthe AP 1002 and the STAs (not shown) in the WLAN in order to extend thecoverage area of the AP 1002. The RE 1010 and AP 1002 may be exampleimplementations of the AP 102 of FIG. 1 , the AP 1902 of FIG. 19A or theSTA 1904 of FIG. 19B.

The RE 1010 may include a measurement unit 1018. The measurement unit1018 may determine distances from the RE 1010 to APs based on RTTinformation. The measurement unit 1018 may determine a distance from theRE 1010 to the AP 1002 based on RTT information derived from FTM framesexchanged with the AP 1002. The FTM frames may include timestamps thatmay be used to derive an RTT between the RE 1010 and the AP 1002. Usingthe RTT, the measurement unit 1018 may determine a first distancebetween the RE 1010 and the AP 1002.

Initially, the RE 1010 may be at a first location 1026. A first distancethreshold may indicate a minimum acceptable distance 1012 between the RE1010 and the AP 1002. A second distance threshold may indicate a maximumacceptable distance 1016 between the RE 1010 and AP 1002. A distancerange 1008 may include a range of acceptable distances between the RE1010 and AP 1002. The circles 1004 and 1006 illustrate a spatialrelationship between the RE 1010 and the minimum acceptable distance1012, the maximum acceptable distance 1016 and the distance range 1008.Initially, the RE 1010 is farther than the maximum acceptable distancefrom the AP 1002 (outside the circle 1006) and outside the range ofacceptable distances (not between the circles 1004 and 1006).

The RE 1010 also may include a placement unit 1020. The placement unit1020 may perform operations for coarse placement of the RE 1010 andoperations for fine placement of the RE 1010. For coarse placement, theRE 1010 may compare the first distance from itself to the AP 1002 to thefirst distance threshold and the second distance threshold to determinewhether the RE 1010 is located within the distance range 1008 (betweenthe circles 1004 and 1006). If the RE 1010 is located outside thedistance range 1008, the RE 1010 may determine whether it is locatedinside the minimum acceptable distance (inside the circle 1004). If theRE 1010 is located inside the minimum acceptable distance, the RE 1010may provide a coarse placement indicator indicating to move the RE 1010farther from the AP 1002. If the RE 1010 is located outside the maximumacceptable distance (outside the circle 1006), the RE 1010 may provide acoarse placement indicator indicating to move the RE 1010 nearer to theAP 1002.

At the first location 1026, the RE 1010 is farther from the AP 1002 thanthe maximum acceptable distance. The placement unit 1020 may compare thefirst distance to the AP 1002 to the first and second distancethresholds and determine that the RE 1010 is farther than the maximumacceptable distance from the AP 1002. In response to determining the RE1010 is farther than the maximum acceptable distance from the AP 1002,the RE 1010 may provide a coarse placement indicator indicating to movethe RE 1010 nearer to the AP 1002.

In response to the coarse placement indicator, the RE 1010 may berelocated to a second location 1028. The RE 1010 may repeat operationsfor coarse placement until it is located in the distance range 1008.Continuing with coarse placement, the RE 1010 may determine a seconddistance between itself and the AP 1002, and determine whether it islocated in the distance range 1008. At the second location 1028, the RE1010 is within the distance range 1008. If the RE 1010 is within thedistance range, it presents a coarse placement indicator indicating toleave the RE 1010 at its current location.

The placement unit 1020 may include distance information 1022 and signalinformation 1024. The distance information 1022 may indicaterelationships between distances from the RE 1010 to the AP 1002, thedistance thresholds and the coarse placement indicators. For example,the relationships 1030 may include:

-   -   1) if distance<first distance threshold (shown as DT1 in FIG. 10        ), provide a coarse placement indicator (shown as CPI in FIG. 10        ) to move farther from the AP 1002 (see distance information        1030 in FIG. 10 );    -   2) if second distance threshold (shown as DT2 in FIG. 10        )≥distance≥first distance threshold (DT1), provide a coarse        placement indicator to remain at the location (see distance        information 1030 in FIG. 10 ); and    -   3) if distance>second distance threshold (DT2), provide a coarse        placement indicator to move nearer the AP (see distance        information 1030 in FIG. 10 ).        The distance thresholds and relationships may be configured to        expand the coverage area of the AP 1002 and to provide suitable        signal strength to the RE 1010. The distance information 1022        may include one or more distance thresholds, coarse placement        indicators, and other information suitable for performing coarse        placement of the RE 1010.

In some implementations, the RE 1010 also may perform operations forfine placement of the RE 1010. For fine placement, the RE 1010 mayprovide indications about placing the RE 1010 based on signal strengths.For example, the RE 1010 may obtain an RSSI associated with the AP 1002.The placement unit 1020 may determine a fine placement indicator basedon the RSSI, and provide the fine placement indicator to assist inplacing the RE 1010 in the environment, as described further in FIG. 11.

FIG. 11 shows a system diagram of an example WLAN including an REconfigured to perform operations for fine placement based on signalstrength information obtained from an AP. FIG. 11 is described withreference to FIG. 10 , and as described in FIG. 10 , the WLAN 1000 mayinclude the RE 1010 and the AP 1002.

As shown in FIG. 11 , the RE 1010 may be inside the distance range 1008at location 1028. The distance range 1008 may be the acceptable distancerange for the coarse placement of the RE 1010. If inside the distancerange 1008, the RE 1010 may perform operations for fine placement. Forfine placement, the RE 1010 may determine a signal strength of the AP1002. The RE 1010 may establish a network association 1102 with the AP1002 to determine a signal strength for the AP 1002. The signal strengthmay be represented by an RSSI. The RE 1010 may compare the signalstrengths to one or more signal strength thresholds to determine whetherthe signal strength is too high, too low, or within an acceptable signalstrength range.

A first signal strength threshold may indicate a maximum acceptablesignal strength from the AP 1002. A second signal strength threshold mayindicate a minimum acceptable signal strength from the AP 1002. A signalstrength range may indicate a range of acceptable signal strengths fromthe AP 1002. If the signal strength is greater than the first signalstrength threshold, the RE 1010 may provide a fine placement indicatorindicating to move farther from the AP 1002. If the signal strength isless than the second signal threshold, the RE 1010 may provide a fineplacement indicator indicating to move nearer to the AP 1002. If thesignal strength is greater than or equal to the second signal strengththreshold and less than or equal to the first signal strength threshold,the RE 1010 may provide a fine placement indicator indicating to leavethe RE 1010 at its current location.

As noted, the placement unit 1020 may include signal information 1024.The signal information 1024 may indicate relationships between signalstrengths to the AP, the signal strength thresholds and the fineplacement indicators. For example, the relationships 1104 may include:

-   -   1) if signal strength (shown as SS in FIG. 11 ) is greater than        the first signal strength threshold (shown as SST1), provide a        fine placement indicator (shown as FPI) indicating to move        farther from the AP 1002;    -   2) if the signal strength is less than or equal to the first        signal strength threshold (SST1) and the signal strength is        greater than or equal to the second signal strength threshold        (shown as SST2), provide a fine placement indicator indicating        to remain at the current location; and    -   3) if signal strength is less than the second signal strength        threshold (SST2), provide a fine placement indicator indicating        to move nearer the AP 1002. The signal strength thresholds and        relationships may be configured to expand the coverage area of        the AP 1002 and to provide suitable signal strength to the RE        1010. The signal information 1024 may include one or more signal        strength thresholds, fine placement indicators and other        information suitable for performing fine placement of the RE        1010.

FIG. 12 depicts a process 1200 illustrating example operations performedby an apparatus of a first WLAN device for using RTT information toplace an RE in an environment. The process 1200 may be performed by awireless communication device such as the wireless communication device1800 or the electronic device 2000 described with reference to FIGS. 18and 20 , respectively. In some implementations, the process 1200 may beperformed by a wireless communication device operating as or within anAP, such as one of the APs 102, 310, 312, and 1902 described withreference to FIGS. 1, 3, 4, 5 and 19A, respectively. In someimplementations, the process 1200 may be performed by an RE, such as theRE 1010 described with reference to FIGS. 10 and 11 , respectively.

At block 1210, the apparatus of the first WLAN device may determine afirst distance from the first WLAN device to a second WLAN device based,at least in part, on FTM frames exchanged with the second WLAN device.

At block 1220, the apparatus of the first WLAN device may determinewhether the first WLAN device is located within a distance range of thesecond WLAN device based, at least in part, on the first distance. Insome implementations, the apparatus of the first WLAN device can beconfigured to provide coarse placement assistance. The coarse placementassistance may include a coarse placement indicator.

At block 1230, the apparatus of the first WLAN device may determine asignal strength associated with the second WLAN device in response tothe second WLAN device being within the distance range.

At block 1240, the apparatus of the first WLAN device may compare thesignal strength to one or more signal strength thresholds.

At block 1250, the apparatus of the first WLAN device may provide a fineplacement indicator based on the comparison.

FIG. 13 depicts a process 1300 illustrating example operations performedby an apparatus of a first WLAN device for using RTT information toplace an RE in an environment. The process 1300 may be performed by awireless communication device such as the wireless communication device1800 or the electronic device 2000 described with reference to FIGS. 18and 20 , respectively. In some implementations, the process 1300 may beperformed by a wireless communication device operating as or within anAP, such as one of the APs 102, 310, 312, 1902 and 2000 described withreference to FIGS. 1, 3, 4, 5, 19A and 20 , respectively. In someimplementations, the process 1300 may be performed by an RE, such as theRE 1010 described with reference to FIGS. 10 and 11 , respectively.

At block 1310, the apparatus of the first WLAN device may determine afirst distance from the first WLAN device to a second WLAN device based,at least in part, on FTM frames exchanged with the second WLAN device.

At block 1320, the apparatus of the first WLAN device may determinewhether the first WLAN device is located within a distance range of thesecond WLAN device based, at least in part, on the first distance. Insome implementations, the apparatus of the first WLAN device can beconfigured to provide coarse placement assistance. The coarse placementassistance may include a coarse placement indicator.

At block 1330, the apparatus of the first WLAN device may determinechannel state information (CSI) associated with the second WLAN devicein response to the second WLAN device being within the distance range.

At block 1340, the apparatus of the first WLAN device may compare theCSI to one or more CSI thresholds.

At block 1350, the apparatus of the first WLAN device may provide a fineplacement indicator based on the comparison.

FIG. 14 depicts a process 1400 illustrating example operations forcoarse placement of an RE in a WLAN that may have an FTM-capable AP. Foran FTM-capable AP, the RE may use FTM frames in a process for coarseplacement of the RE. The process 1400 may be performed by a wirelesscommunication device such as the wireless communication device 1800 orthe electronic device 2000 described with reference to FIGS. 18 and 20 ,respectively. In some implementations, the process 1400 may be performedby a wireless communication device operating as or within an AP, such asthe RE 1010 described with reference to FIGS. 10 and 11 , respectively.The description of the flowchart 1400 will refer to the RE 1010 andother devices described with reference to FIG. 10 .

At block 1402, the RE 1010 may determine whether the AP 1002 isFTM-capable. The AP 1002 may receive a capabilities element indicatingthe RE 1010 is capable of acting as an FTM responder. The capabilitieselement may be included in a beacon or in information exchanged duringassociation. If the RE 1010 receives an information element indicatingthe AP 1002 is capable of acting as an FTM responder, the AP 1002 isFTM-capable. Otherwise, the RE is not FTM-capable. If the AP 1002 isFTM-capable, operations continue at block 1404. Otherwise, operationscontinue at block 1422.

At block 1404, the RE 1010 may exchange FTM frames with the AP 1002. TheFTM frames may include timestamps or other timing information that maybe used to derive an RTT from the RE to the AP. The RE 1010 may exchangethe FTM frames without creating a network association with the AP 1002.

At block 1406, the RE 1010 may determine a distance based on the FTMframes. The RE 1010 may determine the distance based on the RTTassociated with the FTM frames.

At block 1408, the RE 1010 may compare the distance to one or moredistance thresholds. For example, the RE 1010 may compare the distanceto two distance thresholds. A first distance threshold may indicate aminimum distance between the RE 1010 and the AP 1002. The seconddistance threshold may indicate a maximum distance between the RE 1010and the AP 1002. The first and second distance thresholds together mayindicate a distance range in which to place the RE 1010. If the distance(determined at block 1406) is less than the first distance threshold (atblock 1410), operations continue at block 1412. If the first distance isgreater than the first distance threshold (at block 1410), operationscontinue at block 1414.

At block 1412, the RE 1010 may provide a coarse placement indicatorindicating to move the RE farther from the AP 1002. The operationscontinue at block 1404. The RE 1010 may repeat operations for coarseplacement until the RE 1010 is within the distance range of the AP 1002.

At block 1414, the RE 1010 may determine whether the distance(determined at block 1406) is greater than the second distancethreshold. For example, the second distance threshold may indicate amaximum distance between the RE 1010 and the AP 1002. The RE 1010 maydetermine whether the distance between the RE 1010 and the AP 1002 isgreater than the maximum distance. If the distance is greater than thesecond distance threshold, operations continue at block 1416. If thedistance is not greater than the second distance threshold, operationscontinue at block 1418.

At block 1416, the RE 1010 may provide a coarse placement indicatorindicating to move nearer to the AP. For example, the RE 1010 mayprovide the coarse placement indicator by flashing a light indicating tomove the RE 1010 nearer to the AP 1002. Coarse placement indicators mayinclude or be associated with any suitable media, such as audio, sound,video and flashing lights. The RE 1010 may present the media. The RE1010 may cause presentation of the media by providing the coarseplacement indicator to another device, such as a WLAN device or anysuitable device that is not connected to the WLAN 1000. The RE 1010 mayrepeat operations for coarse placement until the RE 1010 is within thedistance range of the AP 1002.

At block 1418, the RE 1010 may provide a coarse placement indicatorindicating to remain at the current location. For example, the RE 1010may be located within a distance range of the AP 1002. Because the RE1010 is within the distance range, the RE 1010 may provide a coarseplacement indicator indicating to remain at the current location.

Referring back to block 1402, if the AP 1002 is not FTM-capable,operations continue at block 1422. If the AP is not FTM-capable, the RE1010 does not perform coarse placement of the RE 1010 based on RTTinformation received from the AP 1002. Instead, the RE 1010 may usesignal strength to assist in placing the RE 1010 in the environment. Atblock 1422, the RE 1010 may create a network association with the AP1002.

At block 1424, the RE 1010 may determine the signal strength of the AP1002. The RE 1010 may determine an RSSI for the AP 1002.

At block 1426, the RE 1010 may provide an indication about placing theRE 1010 based on the signal strength. If signal strength is too high,the RE 1010 may provide an indication to move farther from the AP 1002.If the signal strength is too low, the RE 1010 may provide an indicationto move closer to the AP 1002. If the signal strength is within a signalstrength range, the RE 1010 may provide an indication indicating toremain at its current location. Although the operations at blocks 1422,1424 and 1426 relate to signal strength and placing the RE 1010, thoseoperations may differ from operations for fine placement of the RE 1010described herein.

FIG. 15 depicts example operations of a process 1500 for coarse and fineplacement of an RE in a WLAN that includes one or more FTM-capable APs.The process 1500 may be performed by a wireless communication devicesuch as the wireless communication device 1800 or the electronic device2000 described with reference to FIGS. 18 and 20 , respectively. In someimplementations, the process 1500 may be performed by a wirelesscommunication device operating as or within an AP, such as the RE 1010described with reference to FIGS. 10 and 11 , respectively. Thedescription of the flowchart 1500 will refer to the RE 1010 and otherdevices described with reference to FIG. 10 .

At block 1502, the RE 1010 may determine whether it has established anetwork association with the AP 1002. If no network association has beenestablished, operations continue at block 1502. If the RE 1010 hasestablished a network association with the AP 1002, the RE 1010 may havereceived a capabilities element indicating the AP 1002 is capable ofacting as an FTM responder. If the RE 1010 has established a networkassociation with the AP 1002, the operations continue at block 1504.

At block 1504, the RE 1010 may exchange FTM frames with the AP 1002. TheFTM frames may include timestamps or other timing information that maybe used to derive an RTT from the RE 1010 to the AP 1002.

At block 1506, the RE 1010 may determine a distance based on the FTMframes. The RE may determine the distance based on the RTT associatedwith the FTM frames.

At block 1508, the RE 1010 may compare the distance to two distancethresholds. A first distance threshold may indicate a minimum distancebetween the RE 1010 and the AP 1002. The second distance threshold mayindicate a maximum distance between the RE 1010 and the AP 1002. Thefirst and second distance thresholds together may indicate a distancerange in which to place the RE 1010. If the distance (determined atblock 1506) is less than the first distance threshold, operationscontinue at block 1512. If the first distance is greater than the firstdistance threshold, the operations continue at block 1514.

At block 1512, the RE 1010 may provide a coarse placement indicatorindicating to move the RE 1010 farther from the AP 1002. The operationscontinue at block 1504. The RE 1010 may repeat operations for coarseplacement until the RE 1010 is within the distance range of the AP 1002.

At block 1514, the RE 1010 may determine whether the distance(determined at block 1506) is greater than the second distancethreshold. For example, the second distance threshold may indicate amaximum distance between the RE 1010 and the AP 1002. The RE 1010 maydetermine whether the distance between the RE 1010 and the AP 1002 isgreater than the maximum distance. If the distance is greater than thesecond distance threshold, operations continue at block 1516. If thedistance is not greater than the second distance threshold, theoperations continue at block 1518.

At block 1516, the RE 1010 may provide a coarse placement indicatorindicating to move nearer to the AP. For example, the RE 1010 mayprovide the coarse placement indicator by flashing a light indicating tomove the RE 1010 nearer to the AP 1002. The RE 1010 may repeatoperations for coarse placement until the RE 1010 is within the distancerange of the AP 1002.

At block 1518, the RE 1010 may provide a coarse placement indicatorindicating to remain at the current location. For example, the RE 1010may be located within a distance range of the AP 1002. Because the RE1010 is within the distance range, the RE 1010 may provide a coarseplacement indicator indicating to remain at the current location. Theprocess may continue at block 1622 which is shown in FIG. 16 .

FIG. 16 illustrates additional example operations of the process 1500for coarse and fine placement of an RE in a WLAN that includes one ormore FTM-capable APs. From block 1518 (shown in FIG. 15 ), operationsmay continue at block 1622.

At block 1622, the RE 1010 may determine a signal strength associatedwith the AP 1002. For example, the RE 1010 may determine an RSSI for theAP 1002.

At block 1624, the RE 1010 may determine whether signal strength is lessthan a first signal strength threshold. The first signal strengththreshold may indicate a minimum signal strength with respect to the AP1002. If the signal strength is less than the first signal strengththreshold, operations continue at block 1626. Otherwise, the operationscontinue at block 1628.

At block 1628, the RE 1010 may determine whether the signal strength isgreater than a second signal strength threshold. The second signalstrength threshold may indicate a maximum signal strength with respectto the AP 1002. If the signal strength is greater than the second signalstrength threshold, the operations continue at block 1632. If the signalstrength is less than the second signal strength threshold, theoperations continue at block 1630.

At block 1632, the RE 1010 may provide a fine placement indicatorindicating to move farther from to the AP 1002. Operations continue atblock 1504 (shown in FIG. 15 ).

At block 1630, the RE 1010 may provide a fine placement indicatorindicating to remain at the current location. For operations to arriveat block 1630, the signal strength is within a signal strength rangegreater than or equal to the minimum signal strength and less than orequal to the maximum signal strength. Because the signal strength iswithin the signal strength range, the RE 1010 may provide the fineplacement indicator indicating to remain at the current location.

Referring back to block 1624, if the signal strength is less than thefirst signal strength threshold, the operations continue at block 1626.At block 1626, the RE 1010 may provide a fine placement indicatorindicating to move nearer to the AP 1002. The operations may continue atblock 1504 (shown in FIG. 15 ).

FIG. 17 depicts example operations of a process 1700 for coarse and fineplacement of an RE in a WLAN using channel state information (CSI). Theprocess 1700 may be performed by a wireless communication device such asthe wireless communication device 1800 or the electronic device 2000described with reference to FIGS. 18 and 20 , respectively. In someimplementations, the process 1700 may be performed by a wirelesscommunication device operating as or within an AP, such as the RE 1010described with reference to FIGS. 10 and 11 , respectively. Thedescription of the flowchart 1700 will refer to the RE 1010 and otherdevices described with reference to FIG. 10 .

In some implementations, the RE 1010 may perform operations for coarseplacement shown in FIG. 15 . After performing block 1518, the RE 1010may perform the process 1700, which begins at block 1722. In the process1700, the RE 1010 may use CSI to determine a fine placement in anenvironment.

At block 1722, the RE 1010 may determine the CSI from communicationsreceived from the AP 1002. The CSI information may be instantaneous CSIor short-term CSI. In some implementations, the RE 1010 may estimate theCSI from communications received from the AP 1002 on a per subcarrierbasis, such as on a per Orthogonal Frequency Division Multiplexing(OFDM) subcarrier basis. The CSI determined by the receiving device(such as the RE 1010) also may be referred to as a Receiver CSI (orCSIR). The CSI may indicate channel properties of a communicationchannel between the AP 1002 and the RE 1010 on a per subcarrier basis.For example, the CSI may indicate how signals propagate from the AP 1002to the RE 1010 and may represent the combined effects of scattering,fading, and power decay over the distance between the AP 1002 and the RE1010. In some implementations, the CSI may indicate a CSI amplitude on aper subcarrier basis. The CSI amplitude may indicate the signal strengthon a per subcarrier basis. In some implementations, the CSI also mayindicate a CSI phase on a per subcarrier basis.

At block 1724, the RE 1010 may determine whether the CSI is less than afirst CSI threshold. In some implementations, the CSI may be the CSIamplitude and the first CSI threshold may be a first CSI amplitudethreshold. In some implementations, the CSI may be an aggregate of theCSI amplitudes derived on a per subcarrier basis, which may be referredto as an aggregate CSI amplitude. For example, the RE 1010 may determinethe aggregate CSI amplitude by determining an average of the CSIamplitudes derived on a per subcarrier basis. As another example, the RE1010 may determine the aggregate CSI by determining an average after asum of the squared values of each CSI amplitude derived on a persubcarrier basis. The first CSI amplitude threshold may indicate theminimum aggregate CSI amplitude. In some implementations, the RE 1010may compare the aggregate CSI amplitude to the first CSI amplitudethreshold to determine whether the aggregate CSI amplitude is less thanthe first CSI amplitude threshold. If the CSI is less than the first CSIthreshold, the flow continues at block 1728. Otherwise, the flowcontinues at block 1726.

At block 1726, the RE 1010 may determine whether the CSI is greater thana second CSI threshold. In some implementations, the second CSIthreshold may be a second CSI amplitude threshold. The second CSIamplitude threshold may indicate the maximum aggregate CSI amplitude. Insome implementations, the RE 1010 may compare the aggregate CSIamplitude to the second CSI amplitude threshold to determine whether theaggregate CSI amplitude is greater than the second CSI amplitudethreshold. If the CSI is greater than the second CSI threshold, theoperations continue at block 1732. If the signal strength is less thanthe second signal strength threshold, the operations continue at block1730.

At block 1732, the RE 1010 may provide a fine placement indicatorindicating to move farther from the AP 1002. Operations continue atblock 1504 (shown in FIG. 15 ).

At block 1730, the RE 1010 may provide a fine placement indicatorindicating to remain at the current location. For operations to arriveat block 1730, the CSI may be within a CSI range that is greater than orequal to the minimum CSI and less than or equal to the maximum CSI.Because the CSI is within the CSI range, the RE 1010 may provide thefine placement indicator indicating to remain at the current location.

Referring back to block 1724, if the CSI is less than the first CSIthreshold, the operations continue at block 1728. At block 1728, the RE1010 may provide a fine placement indicator indicating to move nearer tothe AP 1002. The operations may continue at block 1504 (shown in FIG. 15).

In some implementations, the network 1000 may leverage the operationsrelated to CSI from a transmitting device (CSIT) and CSIR to provideplacement assistance for the AP 1002.

In some implementations, the RE 1010 also may use CSIT in the processfor providing placement guidance. The RE 1010 may obtain CSITinformation from the AP 1002 (such as at block 1722). In someimplementations, the RE 1010 may compare CSIT to CSIR to determineinformation related to one or more of scattering, fading and power decay(such as at block 1724). This comparison of CSIT to CSIR may provide avalue greater than, equal to or less than a first CSI threshold. If thevalue is less than the first CSI threshold (such as at block 1724), theRE 1010 may provide a fine placement indicator to move nearer to the AP1002 (such as at block 1728) or the RE 1010 may make further comparisonto a second CSI threshold (such as at block 1726). If the comparison ofCSIT to CSIR is greater than the second CSI threshold, the RE 1010 mayprovide a fine placement indicator to remain at its current location(such as block 1730). Otherwise, the RE may provide a fine placementindicator to move farther from the AP 1002 (such as at block 1732).

FIG. 18 shows a block diagram of an example wireless communicationdevice 1800. In some implementations, the wireless communication device1800 can be an example of a device for use in a STA such as one of theSTAs 104 described herein. In some implementations, the wirelesscommunication device 1800 can be an example of a device for use in an APsuch as the AP 102 described herein. The wireless communication device1800 may be generally referred to as an apparatus or a wirelesscommunication apparatus. The wireless communication device 1800 iscapable of transmitting (or outputting for transmission) and receivingwireless communications (for example, in the form of wireless packets).For example, the wireless communication device 1800 can be configured totransmit and receive packets in the form of PPDUs and MPDUs conformingto an IEEE 802.11 standard, such as that defined by the IEEE 802.11-2016specification or amendments thereof including, but not limited to,802.11ah, 802.11ad, 802.11 ay, 802.11ax, 802.11az, 802.11ba and802.11be, in addition to future 802.11 standards.

The wireless communication device 1800 can be, or can include, a chip,system on chip (SoC), chipset, package or device that includes one ormore modems 1802, for example, a Wi-Fi (IEEE 802.11 compliant) modem. Insome implementations, the one or more modems 1802 (collectively “themodem 1802”) additionally include a WWAN modem (for example, a 3GPP 4GLTE or 5G compliant modem). In some implementations, the wirelesscommunication device 1800 also includes one or more radios 1804(collectively “the radio 1804”). In some implementations, the wirelesscommunication device 1800 further includes one or more processors,processing blocks or processing elements (collectively “the processor1806”) and one or more memory blocks or elements (collectively “thememory 1808”).

The modem 1802 can include an intelligent hardware block or device suchas, for example, an application-specific integrated circuit (ASIC) amongother possibilities. The modem 1802 is generally configured to implementa PHY layer. For example, the modem 1802 is configured to modulatepackets and to output the modulated packets to the radio 1804 fortransmission over the wireless medium. The modem 1802 is similarlyconfigured to obtain modulated packets received by the radio 1804 and todemodulate the packets to provide demodulated packets. In addition to amodulator and a demodulator, the modem 1802 may further include digitalsignal processing (DSP) circuitry, automatic gain control (AGC), acoder, a decoder, a multiplexer and a demultiplexer. For example, whilein a transmission mode, data obtained from the processor 1806 isprovided to a coder, which encodes the data to provide encoded bits. Theencoded bits are mapped to points in a modulation constellation (using aselected MCS) to provide modulated symbols. The modulated symbols may bemapped to a number N_(SS) of spatial streams or a number N_(STS) ofspace-time streams. The modulated symbols in the respective spatial orspace-time streams may be multiplexed, transformed via an inverse fastFourier transform (IFFT) block, and subsequently provided to the DSPcircuitry for Tx windowing and filtering. The digital signals may beprovided to a digital-to-analog converter (DAC). The resultant analogsignals may be provided to a frequency upconverter, and ultimately, theradio 1804. In implementations involving beamforming, the modulatedsymbols in the respective spatial streams are precoded via a steeringmatrix prior to their provision to the IFFT block.

While in a reception mode, digital signals received from the radio 1804are provided to the DSP circuitry, which is configured to acquire areceived signal, for example, by detecting the presence of the signaland estimating the initial timing and frequency offsets. The DSPcircuitry is further configured to digitally condition the digitalsignals, for example, using channel (narrowband) filtering, analogimpairment conditioning (such as correcting for I/Q imbalance), andapplying digital gain to ultimately obtain a narrowband signal. Theoutput of the DSP circuitry may be fed to the AGC, which is configuredto use information extracted from the digital signals, for example, inone or more received training fields, to determine an appropriate gain.The output of the DSP circuitry also is coupled with the demodulator,which is configured to extract modulated symbols from the signal and,for example, compute the logarithm likelihood ratios (LLRs) for each bitposition of each subcarrier in each spatial stream. The demodulator iscoupled with the decoder, which may be configured to process the LLRs toprovide decoded bits. The decoded bits from all of the spatial streamsare fed to the demultiplexer for demultiplexing. The demultiplexed bitsmay be descrambled and provided to the MAC layer (the processor 1806)for processing, evaluation or interpretation.

The radio 1804 generally includes at least one radio frequency (RF)transmitter (or “transmitter chain”) and at least one RF receiver (or“receiver chain”), which may be combined into one or more transceivers.For example, the RF transmitters and receivers may include various DSPcircuitry including at least one power amplifier (PA) and at least onelow-noise amplifier (LNA), respectively. The RF transmitters andreceivers may in turn be coupled to one or more antennas. For example,in some implementations, the wireless communication device 1800 caninclude, or be coupled with, multiple transmit antennas (each with acorresponding transmit chain) and multiple receive antennas (each with acorresponding receive chain). The symbols output from the modem 1802 areprovided to the radio 1804, which transmits the symbols via the coupledantennas. Similarly, symbols received via the antennas are obtained bythe radio 1804, which provides the symbols to the modem 1802. In someimplementations, the radio 1804 and the one or more antennas may formone or more network interfaces (which also may be referred to as“interfaces”).

The processor 1806 can include an intelligent hardware block or devicesuch as, for example, a processing core, a processing block, a centralprocessing unit (CPU), a microprocessor, a microcontroller, a digitalsignal processor (DSP), an application-specific integrated circuit(ASIC), a programmable logic device (PLD) such as a field programmablegate array (FPGA), discrete gate or transistor logic, discrete hardwarecomponents, or any combination thereof designed to perform the functionsdescribed herein. The processor 1806 processes information receivedthrough the radio 1804 and the modem 1802, and processes information tobe output through the modem 1802 and the radio 1804 for transmissionthrough the wireless medium. For example, the processor 1806 mayimplement a control plane and MAC layer configured to perform variousoperations related to the generation and transmission of MPDUs, framesor packets. The MAC layer is configured to perform or facilitate thecoding and decoding of frames, spatial multiplexing, space-time blockcoding (STBC), beamforming, and OFDMA resource allocation, among otheroperations or techniques. In some implementations, the processor 1806may generally control the modem 1802 to cause the modem to performvarious operations described above.

The memory 1808 can include tangible storage media such as random-accessmemory (RAM) or read-only memory (ROM), or combinations thereof. Thememory 1808 also can store non-transitory processor- orcomputer-executable software (SW) code containing instructions that,when executed by the processor 1806, cause the processor to performvarious operations described herein for wireless communication,including the generation, transmission, reception and interpretation ofMPDUs, frames or packets. For example, various functions of componentsdisclosed herein, or various blocks or steps of a method, operation,process or algorithm disclosed herein, can be implemented as one or moremodules of one or more computer programs.

In some implementations, the wireless communication device 1800 mayinclude a measurement unit (not shown) and a steering unit (not shown).The measurement unit and the steering unit may be similar to themeasurement unit 306 and the steering unit 308 described with referenceto FIG. 3 and may implement any of the operation for location awaresteering described herein.

In some implementations, the wireless communication device 1800 mayinclude a measurement unit (not shown) and a placement unit (not shown)similar to the measurement unit 1018 and placement unit 1020 describedwith reference to FIG. 10 and may implement any of the operations forcoarse and fine placement described herein.

In some implementations, the measurement unit, placement unit andsteering unit may be implemented by the processor 1806 and the memory1808. The memory 1808 may include computer instructions executable bythe processor 1806 to implement the functionality of the sounding signalunit. Any of these functionalities may be partially (or entirely)implemented in hardware or on the processor 1806.

In some implementations, the processor 1806 and the memory 1808 of thewireless communication device 1800 may be referred to as a processingsystem. A processing system may generally refer to a system or series ofmachines or components that receives inputs and processes the inputs toproduce a set of outputs (which may be passed to other systems orcomponents of, for example, one of the STAs 104 or one of the APs 102).In some implementations, the processing system may include the processor1806, the memory 1808, and one or more other components of the wirelesscommunication device 1800, such as the modem 1802.

In some implementations, the processing system of a STA 104 mayinterface with other components of the STA 104, and may processinformation received from other components (such as inputs or signals),output information to other components, etc. For example, a chip ormodem of the STA 104 (such as the wireless communication device 1800)may include a processing system and one or more interfaces. The one ormore interfaces may include a first interface to receive or obtaininformation, and a second interface to output, transmit or provideinformation. In some cases, the first interface may refer to aninterface between the processing system of the chip or modem and areceiver, such that the STA 104 may receive information or signalinputs, and the information may be passed to the processing system. Insome cases, the second interface may refer to an interface between theprocessing system of the chip or modem and a transmitter, such that theSTA 104 may transmit information output from the chip or modem. A personhaving ordinary skill in the art will readily recognize that the secondinterface also may obtain or receive information or signal inputs, andthe first interface also may output, transmit or provide information.

In some implementations, the processing system of an AP 102 mayinterface with other components of the AP 102, and may processinformation received from other components (such as inputs or signals),output information to other components, etc. For example, a chip ormodem of the AP 102 (such as the wireless communication device 1800) mayinclude a processing system, a first interface to receive or obtaininformation, and a second interface to output, transmit or provideinformation. In some cases, the first interface may refer to aninterface between the processing system of the chip or modem and areceiver, such that the AP 102 may receive information or signal inputs,and the information may be passed to the processing system. In somecases, the second interface may refer to an interface between theprocessing system of the chip or modem and a transmitter, such that theAP 102 may transmit information output from the chip or modem. A personhaving ordinary skill in the art will readily recognize that the secondinterface also may obtain or receive information or signal inputs, andthe first interface also may output, transmit or provide information.

FIG. 19A shows a block diagram of an example AP 1902. For example, theAP 1902 can be an example implementation of the AP 102 described herein.The AP 1902 includes a wireless communication device (WCD) 1910. Forexample, the wireless communication device 1910 may be an exampleimplementation of the wireless communication device 1800 described withreference to FIG. 18 . The AP 1902 also includes multiple antennas 1920coupled with the wireless communication device 1910 to transmit andreceive wireless communications. In some implementations, the AP 1902additionally includes an application processor 1930 coupled with thewireless communication device 1910, and a memory 1940 coupled with theapplication processor 1930. The AP 1902 further includes at least oneexternal network interface 1950 that enables the AP 1902 to communicatewith a core network or backhaul network to gain access to externalnetworks including the Internet. For example, the external networkinterface 1950 may include one or both of a wired (for example,Ethernet) network interface and a wireless network interface (such as aWWAN interface). Ones of the aforementioned components can communicatewith other ones of the components directly or indirectly, over at leastone bus. The AP 1902 further includes a housing that encompasses thewireless communication device 1910, the application processor 1930, thememory 1940, and at least portions of the antennas 1920 and externalnetwork interface 1950.

FIG. 19B shows a block diagram of an example STA 1904. For example, theSTA 1904 can be an example implementation of the STA 104 describedherein. The STA 1904 includes a wireless communication device 1915. Forexample, the wireless communication device 1915 may be an exampleimplementation of the wireless communication device 1800 described withreference to FIG. 9 . The STA 1904 also includes one or more antennas1925 coupled with the wireless communication device 1915 to transmit andreceive wireless communications. The STA 1904 additionally includes anapplication processor 1935 coupled with the wireless communicationdevice 1915, and a memory 1945 coupled with the application processor1935. In some implementations, the STA 1904 further includes a userinterface (UI) 1955 (such as a touchscreen or keypad) and a display1965, which may be integrated with the UI 1955 to form a touchscreendisplay. In some implementations, the STA 1904 may further include oneor more sensors 1975 such as, for example, one or more inertial sensors,accelerometers, temperature sensors, pressure sensors, or altitudesensors. Ones of the aforementioned components can communicate withother ones of the components directly or indirectly, over at least onebus. The STA 1904 further includes a housing that encompasses thewireless communication device 1915, the application processor 1935, thememory 1945, and at least portions of the antennas 1925, UI 1955, anddisplay 1965.

FIG. 20 shows a block diagram of an example electronic device forimplementing aspects of this disclosure. In some implementations, theelectronic device 2000 may be one of an AP (including any of the APsdescribed herein), a range extender, a station (including any of theSTAs described herein) or other electronic systems. The electronicdevice 2000 can include a processor 2002 (possibly including multipleprocessors, multiple cores, multiple nodes, or implementingmulti-threading, etc.). The electronic device 2000 also can include amemory 2006. The memory 2006 may be system memory or any one or more ofthe possible realizations of computer-readable media described herein.In some implementations, the processor 2002 and the memory 2006 may bereferred to as the processing system. The electronic device 2000 alsocan include a bus 2010 (such as PCI, ISA, PCI-Express, HyperTransport®,InfiniBand®, NuBus,® AHB, AXI, etc.), and one or more network interfaces2004 (which also may be referred to as “interfaces”) that can include atleast one of a wireless network interface (such as a WLAN interface, aBluetooth® interface, a WiMAX® interface, a ZigBee® interface, aWireless USB interface, etc.) and a wired network interface (such as anEthernet interface, a powerline communication interface, etc.). In someimplementations, the electronic device 2000 may support multiple networkinterfaces—each of which is configured to couple the electronic device2000 to a different communication network.

The electronic device 2000 may include a measurement unit 306 and asteering unit 308, which may implement operations for location awaresteering as described herein. In some implementations, the measurementunit 306 and the steering unit 308 may be distributed within theprocessor 2002 and the memory 2006. The measurement unit 306 and thesteering unit 308 may perform some or all the location aware steeringoperations described herein in this disclosure.

The electronic device 2000 may include a measurement unit 1018, aplacement unit 1020, which may implement operations for coarse placementand fine placement of an RE as described herein. In someimplementations, the measurement unit 1018 and the placement unit 1020may be distributed within the processor 2002 and the memory 2006.

The memory 2006 can include computer instructions executable by theprocessor 2002 to implement the functionality of the implementationsdescribed in FIGS. 1-20 . Any of these functionalities may be partially(or entirely) implemented in hardware or on the processor 2002. Forexample, the functionality may be implemented with an applicationspecific integrated circuit, in logic implemented in the processor 2002,in a co-processor on a peripheral device or card, etc. Further,realizations may include fewer or additional components not illustratedin FIG. 20 (such as video cards, audio cards, additional networkinterfaces, peripheral devices, etc.). The processor 2002, the memory2006, and the network interface 2004 are coupled to the bus 2010.Although illustrated as being coupled to the bus 2010, the memory 2006may be coupled to the processor 2002.

FIGS. 1-20 and the operations described herein are examples meant to aidin understanding example implementations and should not be used to limitthe potential implementations or limit the scope of the claims. Someimplementations may perform additional operations, fewer operations,operations in parallel or in a different order, and some operationsdifferently.

As used herein, a phrase referring to “at least one of” a list of itemsrefers to any combination of those items, including single members. Asan example, “at least one of: a, b, or c” is intended to cover: a, b, c,a-b, a-c, b-c, and a-b-c.

The various illustrative logics, logical blocks, modules, circuits andalgorithm processes described in connection with the implementationsdisclosed herein may be implemented as electronic hardware, computersoftware, or combinations of both. The interchangeability of hardwareand software has been described generally, in terms of functionality,and illustrated in the various illustrative components, blocks, modules,circuits and processes described throughout. Whether such functionalityis implemented in hardware or software depends upon the particularapplication and design constraints imposed on the overall system.

The hardware and data processing apparatus used to implement the variousillustrative logics, logical blocks, modules and circuits described inconnection with the aspects disclosed herein may be implemented orperformed with a general purpose single- or multi-chip processor, adigital signal processor (DSP), an application-specific integratedcircuit (ASIC), a field-programmable gate array (FPGA) or otherprogrammable logic device, discrete gate or transistor logic, discretehardware components, or any combination thereof designed to perform thefunctions described herein. A general-purpose processor may be amicroprocessor, or, any conventional processor, controller,microcontroller, or state machine. A processor also may be implementedas a combination of computing devices, e.g., a combination of a DSP anda microprocessor, a plurality of microprocessors, one or moremicroprocessors in conjunction with a DSP core, or any other suchconfiguration. In some implementations, particular processes and methodsmay be performed by circuitry that is specific to a given function.

In one or more aspects, the functions described may be implemented inhardware, digital electronic circuitry, computer software, firmware,including the structures disclosed in this specification and theirstructural equivalents thereof, or in any combination thereof.Implementations of the subject matter described in this specificationalso can be implemented as one or more computer programs, i.e., one ormore modules of computer program instructions, encoded on a computerstorage media for execution by, or to control the operation of, dataprocessing apparatus.

If implemented in software, the functions may be stored on ortransmitted over as one or more instructions or code on acomputer-readable medium. The processes of a method or algorithmdisclosed herein may be implemented in a processor-executable softwaremodule which may reside on a computer-readable medium. Computer-readablemedia includes both computer storage media and communication mediaincluding any medium that can be enabled to transfer a computer programfrom one place to another. A storage media may be any available mediathat may be accessed by a computer. By way of example, and notlimitation, such computer-readable media may include RAM, ROM, EEPROM,CD-ROM or other optical disk storage, magnetic disk storage or othermagnetic storage devices, or any other medium that may be used to storedesired program code in the form of instructions or data structures andthat may be accessed by a computer. Also, any connection can be properlytermed a computer-readable medium. Disk and disc, as used herein,includes compact disc (CD), laser disc, optical disc, digital versatiledisc (DVD), floppy disk, and Blu-Ray′ disc where disks usually reproducedata magnetically, while discs reproduce data optically with lasers.Combinations also can be included within the scope of computer-readablemedia. Additionally, the operations of a method or algorithm may resideas one or any combination or set of codes and instructions on a machinereadable medium and computer-readable medium, which may be incorporatedinto a computer program product.

Various modifications to the implementations described in thisdisclosure may be readily apparent to those skilled in the art, and thegeneric principles defined herein may be applied to otherimplementations without departing from the spirit or scope of thisdisclosure. Thus, the claims are not intended to be limited to theimplementations shown herein but are to be accorded the widest scopeconsistent with this disclosure, the principles and the novel featuresdisclosed herein.

Additionally, a person having ordinary skill in the art will readilyappreciate, the terms “upper” and “lower” are sometimes used for ease ofdescribing the Figures, and indicate relative positions corresponding tothe orientation of the Figure on a properly oriented page and may notreflect the proper orientation of any device as implemented.

Certain features that are described in this specification in the contextof separate implementations also can be implemented in combination in asingle implementation. Conversely, various features that are describedin the context of a single implementation also can be implemented inmultiple implementations separately or in any suitable subcombination.Moreover, although features may be described as acting in certaincombinations and even initially claimed as such, one or more featuresfrom a claimed combination can in some cases be excised from thecombination, and the claimed combination may be directed to asubcombination or variation of a subcombination.

Similarly, while operations are depicted in the drawings in a particularorder, this should not be understood as requiring that such operationsbe performed in the particular order shown or in sequential order, orthat all illustrated operations be performed, to achieve desirableresults. Further, the drawings may schematically depict one more exampleprocess in the form of a flow diagram. However, other operations thatare not depicted can be incorporated in the example processes that areschematically illustrated. For example, one or more additionaloperations can be performed before, after, simultaneously, or betweenany of the illustrated operations. In certain circumstances,multitasking and parallel processing may be advantageous. Moreover, theseparation of various system components in the implementations describedshould not be understood as requiring such separation in allimplementations, and it should be understood that the described programcomponents and systems can generally be integrated together in a singlesoftware product or packaged into multiple software products.Additionally, other implementations are within the scope of thefollowing claims. In some cases, the actions recited in the claims canbe performed in a different order and still achieve desirable results.

In some aspects, a first method for wireless communication in a WLANperformed by an apparatus of a first AP may include determining whethera WLAN device is capable of exchanging FTM frames. The first method mayinclude, in response to determining the WLAN device is capable ofexchanging FTM frames, determining a first distance from the first AP tothe WLAN device based, at least in part, on the FTM frames exchangedwith the WLAN device. The first method may include, in response todetermining the WLAN device is capable of exchanging FTM frames,obtaining an indication of a second distance between a second AP and theWLAN device. The first method may include, in response to determiningthe WLAN device is capable of exchanging FTM frames, determining alocation of the WLAN device based, at least in part, on the firstdistance and the second distance. The first method may include, inresponse to determining the WLAN device is capable of exchanging FTMframes, steering the WLAN device to the second AP based, at least inpart, on the location of the WLAN device.

The first method may include additional aspects, such as any singleaspect or any combination of aspects described below or in connectionwith one or more other methods described elsewhere herein.

In a first aspect, the location is a relative location of the WLANdevice with respect to the first AP and the second AP.

In a second aspect, alone or in combination with the first aspect, thefirst method may include determining a signal strength of a signalreceived from the WLAN device. In the second aspect, the first methodmay include determining that the signal strength is less than a signalstrength threshold, where determining whether a WLAN device is capableof exchanging FTM frames is in response to determining that the signalstrength is less than a signal strength threshold.

In a third aspect, alone or in combination with one or more of the firstand second aspects, determining whether a WLAN device is capable ofexchanging FTM frames may include obtaining, from the WLAN device, acapabilities element indicating the WLAN device is capable of exchangingFTM frames.

In a fourth aspect, alone or in combination with one or more of thefirst through third aspects, determining the first distance is based, atleast in part, on FTM frames exchanged with the WLAN device may includeoutputting the FTM frames for transmission to the WLAN device, obtainingFTM ACKs associated with the FTM frames from the WLAN device,determining a RTT based, at least in part, on the FTM frames and the FTMACKs, and determining the first distance based, at least in part, on theRTT.

In a fifth aspect, alone or in combination with one or more of the firstthrough fourth aspects, steering the WLAN device may include selectingsteering information based, at least in part, on the location of theWLAN device, where the steering information indicates whether to steerthe WLAN device based, at least in part, on the location. In the fifthaspect, steering the WLAN device may include determining to steer theWLAN device to the second AP based, at least in part, on the steeringinformation.

In a sixth aspect, alone or in combination with one or more of the firstthrough fifth aspects, obtaining the indication of the second distancemay include receiving an FTM range report that indicates the seconddistance.

In a seventh aspect, alone or in combination with one or more of thefirst through sixth aspects, the first method may include outputting anFTM request for transmission to the WLAN device. In the seventh aspect,the first method may include obtaining an FTM acknowledgement from theWLAN device. In the seventh aspect, the first method may include, inresponse to obtaining the FTM acknowledgment, exchanging the FTM frameswith the WLAN device.

In an eighth aspect, alone or in combination with one or more of thefirst through seventh aspects, the first method may include obtaining,from the second AP, distance information including the indication of thesecond distance.

In a ninth aspect, alone or in combination with one or more of the firstthrough eighth aspects, the first method may also include obtainingdistance information from other APs in the WLAN, the distanceinformation indicating other distances from the other APs to the WLANdevice.

In a tenth aspect, alone or in combination with one or more of the firstthrough ninth aspects, the first method may include determining a thirddistance from the first AP to the WLAN device based, at least in part,on additional FTM frames exchanged with the WLAN device. In the tenthaspect, the first method may include steering the WLAN device from afirst frequency band of the first AP to a second frequency band of thefirst AP based, at least in part, on the third distance.

In an eleventh aspect, alone or in combination with one or more of thefirst through tenth aspects, the first method may include after steeringthe WLAN device, determining a signal strength of communicationsreceived from the WLAN device. In the eleventh aspect, the first methodmay include, after steering the WLAN device, determining that the signalstrength is greater than a signal strength threshold. In the eleventhaspect, the first method may include, after steering the WLAN device,updating steering information to indicate the location and the signalstrength.

In some aspects, a second method for wireless communication in a WLANperformed by an apparatus of an AP may include determining whether aWLAN device is capable of exchanging FTM frames. The second method mayinclude, in response to determining the WLAN device is capable ofexchanging the FTM frames, determining a distance from the AP to theWLAN device based, at least in part, on FTM frames exchanged with theWLAN device. The second method may include, in response to determiningthe WLAN device is capable of exchanging the FTM frames, steering theWLAN device from a first frequency band of the AP to a second frequencyband of the AP based, at least in part, on the distance.

The second method may include additional aspects, such as any singleaspect or any combination of aspects described below or in connectionwith one or more other methods described elsewhere herein.

In a first aspect, the second method may include determining a signalstrength of a signal received from the WLAN device. In the first aspect,the second method may include determining that the signal strength isless than a signal strength threshold, where determining whether a WLANdevice is capable of exchanging FTM frames is in response to determiningthat the signal strength is less than a signal strength threshold.

In a second aspect, alone or in combination with the first aspect, thesecond method may include determining the AP has a wireless associationwith the WLAN device via the first frequency band. In the second aspect,the second method may include determining that the WLAN device isoutside a first range of the first frequency band of the AP based, atleast in part, on the distance.

In a third aspect, alone or in combination with one or more of the firstand second aspects, the second method may include determining the WLANis within a second range of the second frequency band.

In a fourth aspect, alone or in combination with one or more of thefirst through third aspects, the second method may include outputtingthe FTM frames for transmission to the WLAN device. In the fourthaspect, the second method may include obtaining FTM ACKs from the WLANdevice.

In a fifth aspect, alone or in combination with one or more of the firstthrough fourth aspects, steering the WLAN device may include selectingsteering information based, at least in part, on the distance from theAP to the WLAN device. In the fifth aspect, the steering the WLAN devicemay include determining to steer the WLAN device to the second frequencyband based, at least in part, on the steering information.

In a sixth aspect, alone or in combination with one or more of the firstthrough fifth aspects, the method may include after steering the WLANdevice, determining a signal strength of communications received fromthe WLAN device. In the sixth aspect, the method may include, aftersteering the WLAN device, determining that the signal strength isgreater than a signal strength threshold. In the sixth aspect, themethod may include, after steering the WLAN device, updating steeringinformation to indicate the distance and the signal strength.

In some aspects, an apparatus of a first AP for wireless communicationmay include a processor configured to determine whether a WLAN device ofa WLAN is capable of exchanging FTM frames. The processor may beconfigured to, in response to a determination that the WLAN device iscapable of exchanging the FTM frames, determine a first distance fromthe first AP to the WLAN device based, at least in part, on FTM framesexchanged with the WLAN device. The processor may be configured to, inresponse to a determination that the WLAN device is capable ofexchanging the FTM frames, obtain an indication of a second distancebetween a second AP and the WLAN device. The processor may be configuredto, in response to a determination that the WLAN device is capable ofexchanging the FTM frames, determine a location of the WLAN devicebased, at least in part, on the first distance and the second distance.The apparatus of the first AP may include an interface configured tooutput a message to steer the WLAN device to the second AP based, atleast in part, on the location of the WLAN device.

The apparatus of the first AP may include additional aspects, such asany single aspect or any combination of aspects described below or inconnection with one or more other apparatuses described elsewhereherein.

In a first aspect, the processor may be further configured to determinea signal strength of a signal received from the WLAN device, anddetermine that the signal strength is less than a signal strengththreshold, where the determination whether a WLAN device is capable ofexchanging FTM frames is in response to determining that the signalstrength is less than a signal strength threshold.

In a second aspect, alone or in combination with the first aspect, theprocessor may be further configured to obtain the indication of thesecond distance from an FTM range report.

In a third aspect, alone or in combination with one or more of the firstand second aspects, the interface may be further configured to outputthe FTM frames for transmission to the WLAN device, and obtain FTM ACKsfrom the WLAN device. In the third aspect, the processor may be furtherconfigured to determine an RTT based on the FTM frames and the FTM ACKs,and determine the first distance based on the RTT.

In a fourth aspect, alone or in combination with one or more of thefirst through third aspects, the processor may be further configured toselect steering information based, at least in part, on the location ofthe WLAN device, where the steering information indicates whether tosteer the WLAN device based, at least in part, on the location. In thefourth aspect, the processor may be further configured to determine tosteer the WLAN device to the second AP based, at least in part, on thesteering information.

In a fifth aspect, alone or in combination with one or more of the firstthrough fourth aspects, the processor may be further configured todetermine the location is outside a first coverage area of a firstfrequency band of the first AP and within a second coverage area of asecond frequency band of the first AP. In the fifth aspect, theprocessor may be further configured to steer the WLAN device from thefirst frequency band of the first AP to the second frequency band of thefirst AP based, at least in part, on the location.

In a sixth aspect, alone or in combination with one or more of the firstthrough fifth aspects, the processor may be further configured todetermine a third distance from the first AP to the WLAN device based,at least in part, on additional FTM frames exchanged with the WLANdevice. In the sixth aspect, the processor may be further configured tosteer the WLAN device from a first frequency band of the first AP to asecond frequency band of the first AP based, at least in part, on thethird distance.

In some aspects, an apparatus for wireless communication of an AP mayinclude a processor configured to determine whether a WLAN device of aWLAN is capable of exchanging FTM frames. The processor may beconfigured to, in response to a determination that the WLAN device iscapable of exchanging the FTM frames, determine a distance from the APto the WLAN device based, at least in part, on FTM frames exchanged withthe WLAN device. The processor may be configured to, in response to adetermination that the WLAN device is capable of exchanging the FTMframes, steer the WLAN device from a first frequency band of the AP to asecond frequency band of the AP based, at least in part, on thedistance.

The apparatus for wireless communication of an AP may include additionalaspects, such as any single aspect or any combination of aspectsdescribed below or in connection with one or more other apparatusesdescribed elsewhere herein.

In a first aspect, the processor may be further configured to determinea signal strength of a signal received from the WLAN device. In thefirst aspect, the processor may be further configured to determine thatthe signal strength is less than a signal strength threshold, where thedetermination whether a WLAN device is capable of exchanging FTM framesis in response to determining that the signal strength is less than asignal strength threshold.

In a second aspect, alone or in combination with the first aspect, theprocessor may be further configured to determine the AP has a wirelessassociation with the WLAN device via the first frequency band, anddetermine that the WLAN device is outside a first coverage area of thefirst frequency band of the AP based, at least in part, on the distance.

In a third aspect, alone or in combination with one or more of the firstand second aspects, the processor may be further configured to selectsteering information based, at least in part, on the distance of theWLAN device, and determine to steer the WLAN device to the secondfrequency band based, at least in part, on the steering information.

What is claimed is:
 1. A method for wireless communication in a wirelesslocal area network (WLAN) performed by an apparatus of a first accesspoint (AP), comprising: obtaining one or more signals from a non-APstation (STA); obtaining, at the AP from the non-AP STA via acapabilities element, an indication of a capability of the non-AP STA toexchange fine timing measurement (FTM) frames in response to a signalstrength of the one or more signals from the non-AP STA being less thana signal strength threshold; performing an FTM frame exchange with thenon-AP STA in accordance with the capability of the non-AP STA toexchange FTM frames, wherein a first distance between the first AP andthe non-AP STA is obtained from the FTM frame exchange; obtaining anindication of a second distance between a second AP and the non-AP STA;and outputting a message to steer the non-AP STA to the second AP inaccordance with the first distance and the second distance.
 2. Themethod of claim 1, wherein the message to steer the non-AP STA to thesecond AP is associated with a relative location of the non-AP STA withrespect to the first AP and the second AP.
 3. The method of claim 1,further comprising: outputting the FTM frames for transmission to thenon-AP STA; obtaining FTM acknowledgements (ACKs) associated with theFTM frames from the non-AP STA; determining a round-trip time (RTT)based, at least in part, on the FTM frames and the FTM ACKs; anddetermining the first distance based, at least in part, on the RTT. 4.The method of claim 1, further comprising: selecting steeringinformation based, at least in part, on a location of the non-AP STA,wherein the steering information indicates whether to steer the non-APSTA based, at least in part, on the location; and determining to steerthe non-AP STA to the second AP based, at least in part, on the steeringinformation.
 5. The method of claim 1, wherein obtaining the indicationof the second distance comprises: receiving an FTM range report thatindicates the second distance.
 6. The method of claim 1, furthercomprising: outputting an FTM request for transmission to the non-APSTA; obtaining an FTM acknowledgement from the non-AP STA; and inresponse to obtaining the FTM acknowledgement, exchanging the FTM frameswith the non-AP STA.
 7. The method of claim 1, further comprising:obtaining, from the second AP, distance information including theindication of the second distance.
 8. The method of claim 1, furthercomprising: obtaining distance information from other APs in the WLAN,the distance information indicating other distances from the other APsto the non-AP STA.
 9. The method of claim 1, further comprising:determining a third distance from the first AP to the non-AP STA based,at least in part, on additional FTM frames exchanged with the non-APSTA; and steering the non-AP STA from a first frequency band of thefirst AP to a second frequency band of the first AP based, at least inpart, on the third distance.
 10. The method of claim 1, wherein, aftersteering the non-AP STA, the method further comprises: determining asignal strength of communications received from the non-AP STA; anddetermining that the signal strength is greater than the signal strengththreshold.
 11. A method for wireless communication in a wireless localarea network (WLAN) performed by an apparatus of an access point (AP),comprising: obtaining one or more signals from a non-AP station (STA);obtaining, at the AP from the non-AP STA via a capabilities element, anindication of a capability of the non-AP STA to exchange fine timingmeasurement (FTM) frames in response to a signal strength of the one ormore signals from the non-AP STA being less than a signal strengththreshold; performing an FTM frame exchange with the non-AP STA inaccordance with the capability of the non-AP STA to exchange FTM frames,wherein a distance between the AP and the non-AP STA is obtained fromthe FTM frame exchange; and outputting a message to steer the non-AP STAfrom a first frequency band to a second frequency band in accordancewith the distance between the AP and the non-AP STA.
 12. The method ofclaim 11, further comprising: determining the AP has a wirelessassociation with the non-AP STA via the first frequency band; anddetermining that the non-AP STA is outside a first range of the firstfrequency band of the AP based, at least in part, on the distance. 13.The method of claim 12, further comprising: determining the non-AP STAis within a second range of the second frequency band.
 14. The method ofclaim 11, further comprising: outputting the FTM frames for transmissionto the non-AP STA; and obtaining FTM acknowledgements (ACKs) from thenon-AP STA.
 15. The method of claim 11, wherein steering the non-AP STAcomprises: selecting steering information based, at least in part, onthe distance from the AP to the non-AP STA; and determining to steer thenon-AP STA to the second frequency band based, at least in part, on thesteering information.
 16. The method of claim 11, wherein, aftersteering the non-AP STA, the method further comprises: determining asignal strength of communications received from the non-AP STA; anddetermining that the signal strength is greater than the signal strengththreshold.
 17. A first access point (AP) for wireless communication,comprising: one or more memories; and one or more processors coupled tothe one or more memories, the one or more processors individually orcollectively configured to cause the first AP to: obtain one or moresignals from a non-AP station (STA); obtain, at the AP from the non-APSTA via a capabilities element, an indication of a capability of thenon-AP STA to exchange fine timing measurement (FTM) frames in responseto a signal strength of the one or more signals from the non-AP STAbeing less than a signal strength threshold; perform an FTM frameexchange with the non-AP STA in accordance with the capability of thenon-AP STA to exchange FTM frames, wherein a first distance between thefirst AP and the non-AP STA is obtained from the FTM frame exchange;obtain an indication of a second distance between a second AP and thenon-AP STA; and output a message to steer the non-AP STA to the secondAP in accordance with the first distance and the second distance. 18.The first AP of claim 17, wherein the one or more processors are furtherconfigured to cause the AP to: obtain the indication of the seconddistance from an FTM range report.
 19. The first AP of claim 17, whereinthe one or more processors are further configured to cause the AP to:output FTM frames for transmission to the non-AP STA; obtain FTMacknowledgements (ACKs) from the non-AP STA; determine a round-trip time(RTT) based on the FTM frames and the FTM ACKs; and determine the firstdistance based on the RTT.
 20. The first AP of claim 17, wherein the oneor more processors are further configured to cause the AP to: selectsteering information based, at least in part, on a location of thenon-AP STA, wherein the steering information indicates whether to steerthe non-AP STA based, at least in part, on the location; and determineto steer the non-AP STA to the second AP based, at least in part, on thesteering information.
 21. The first AP of claim 17, wherein the one ormore processors are further configured to cause the AP to: determine alocation of the non-AP STA is outside a first coverage area of a firstfrequency band of the first AP and within a second coverage area of asecond frequency band of the first AP, and steer the non-AP STA from thefirst frequency band of the first AP to the second frequency band of thefirst AP based, at least in part, on the location.
 22. The first AP ofclaim 17, wherein the one or more processors are further configured tocause the AP to: determine a third distance from the first AP to thenon-AP STA based, at least in part, on additional FTM frames exchangedwith the non-AP STA, and steer the non-AP STA from a first frequencyband of the first AP to a second frequency band of the first AP based,at least in part, on the third distance.
 23. An access point (AP),comprising: one or more memories; and one or more processors coupled tothe one or more memories, the one or more processors individually orcollectively configured to cause the AP to: obtain one or more signalsfrom a non-AP station (STA); obtain, at the AP from the non-AP STA via acapabilities element, an indication of a capability of the non-AP STA toexchange fine timing measurement (FTM) frames in response to a signalstrength of the one or more signals from the non-AP STA being less thana signal strength threshold; perform an FTM frame exchange with thenon-AP STA in accordance with the capability of the non-AP STA toexchange FTM frames, wherein a distance between the AP and the non-APSTA is obtained from the FTM frame exchange; and output a message tosteer the non-AP STA from a first frequency band to a second frequencyband in accordance with the distance between the AP and the non-AP STA.24. The AP of claim 23, wherein the one or more processors are furtherconfigured to cause the AP to: determine the AP has a wirelessassociation with the non-AP STA via the first frequency band; anddetermine that the non-AP STA is outside a first coverage area of thefirst frequency band of the AP based, at least in part, on the distance.25. The AP of claim 23, wherein the one or more processors are furtherconfigured to cause the AP to: select steering information based, atleast in part, on the distance of the non-AP STA; and determine to steerthe non-AP STA to the second frequency band based, at least in part, onthe steering information.